guava-gwt/src-super/com/google/common/collect/super/com/google/common/collect/ImmutableMultimap.java - platform/external/guava - Git at Google

 /*
  * Copyright (C) 2008 The Guava Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.google.common.collect;

 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.collect.CollectPreconditions.checkEntryNotNull;

 import com.google.common.annotations.GwtCompatible;

 import java.io.Serializable;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;

 import javax.annotation.Nullable;

 /**
  * An immutable {@link Multimap}. Does not permit null keys or values.
  *
  * <p>Unlike {@link Multimaps#unmodifiableMultimap(Multimap)}, which is
  * a <i>view</i> of a separate multimap which can still change, an instance of
  * {@code ImmutableMultimap} contains its own data and will <i>never</i>
  * change. {@code ImmutableMultimap} is convenient for
  * {@code public static final} multimaps ("constant multimaps") and also lets
  * you easily make a "defensive copy" of a multimap provided to your class by
  * a caller.
  *
  * <p><b>Note:</b> Although this class is not final, it cannot be subclassed as
  * it has no public or protected constructors. Thus, instances of this class
  * are guaranteed to be immutable.
  *
  * <p>In addition to methods defined by {@link Multimap}, an {@link #inverse}
  * method is also supported.
  *
  * <p>See the Guava User Guide article on <a href=
  * "http://code.google.com/p/guava-libraries/wiki/ImmutableCollectionsExplained">
  * immutable collections</a>.
  *
  * @author Jared Levy
  * @since 2.0 (imported from Google Collections Library)
  */
 @GwtCompatible(emulated = true)
 public abstract class ImmutableMultimap<K, V> extends AbstractMultimap<K, V>
     implements Serializable {

   /** Returns an empty multimap. */
   public static <K, V> ImmutableMultimap<K, V> of() {
     return ImmutableListMultimap.of();
   }

   /**
    * Returns an immutable multimap containing a single entry.
    */
   public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1) {
     return ImmutableListMultimap.of(k1, v1);
   }

   /**
    * Returns an immutable multimap containing the given entries, in order.
    */
   public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1, K k2, V v2) {
     return ImmutableListMultimap.of(k1, v1, k2, v2);
   }

   /**
    * Returns an immutable multimap containing the given entries, in order.
    */
   public static <K, V> ImmutableMultimap<K, V> of(
       K k1, V v1, K k2, V v2, K k3, V v3) {
     return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3);
   }

   /**
    * Returns an immutable multimap containing the given entries, in order.
    */
   public static <K, V> ImmutableMultimap<K, V> of(
       K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
     return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3, k4, v4);
   }

   /**
    * Returns an immutable multimap containing the given entries, in order.
    */
   public static <K, V> ImmutableMultimap<K, V> of(
       K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
     return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5);
   }

   // looking for of() with > 5 entries? Use the builder instead.

   /**
    * Returns a new builder. The generated builder is equivalent to the builder
    * created by the {@link Builder} constructor.
    */
   public static <K, V> Builder<K, V> builder() {
     return new Builder<K, V>();
   }

   /**
    * Multimap for {@link ImmutableMultimap.Builder} that maintains key and
    * value orderings, allows duplicate values, and performs better than
    * {@link LinkedListMultimap}.
    */
   private static class BuilderMultimap<K, V> extends AbstractMapBasedMultimap<K, V> {
     BuilderMultimap() {
       super(new LinkedHashMap<K, Collection<V>>());
     }
     @Override Collection<V> createCollection() {
       return Lists.newArrayList();
     }
     private static final long serialVersionUID = 0;
   }

   /**
    * A builder for creating immutable multimap instances, especially
    * {@code public static final} multimaps ("constant multimaps"). Example:
    * <pre>   {@code
    *
    *   static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
    *       new ImmutableMultimap.Builder<String, Integer>()
    *           .put("one", 1)
    *           .putAll("several", 1, 2, 3)
    *           .putAll("many", 1, 2, 3, 4, 5)
    *           .build();}</pre>
    *
    * <p>Builder instances can be reused; it is safe to call {@link #build} multiple
    * times to build multiple multimaps in series. Each multimap contains the
    * key-value mappings in the previously created multimaps.
    *
    * @since 2.0 (imported from Google Collections Library)
    */
   public static class Builder<K, V> {
     Multimap<K, V> builderMultimap = new BuilderMultimap<K, V>();
     Comparator<? super K> keyComparator;
     Comparator<? super V> valueComparator;

     /**
      * Creates a new builder. The returned builder is equivalent to the builder
      * generated by {@link ImmutableMultimap#builder}.
      */
     public Builder() {}

     /**
      * Adds a key-value mapping to the built multimap.
      */
     public Builder<K, V> put(K key, V value) {
       checkEntryNotNull(key, value);
       builderMultimap.put(key, value);
       return this;
     }

     /**
      * Adds an entry to the built multimap.
      *
      * @since 11.0
      */
     public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
       return put(entry.getKey(), entry.getValue());
     }

     /**
      * Stores a collection of values with the same key in the built multimap.
      *
      * @throws NullPointerException if {@code key}, {@code values}, or any
      *     element in {@code values} is null. The builder is left in an invalid
      *     state.
      */
     public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
       if (key == null) {
         throw new NullPointerException(
             "null key in entry: null=" + Iterables.toString(values));
       }
       Collection<V> valueList = builderMultimap.get(key);
       for (V value : values) {
         checkEntryNotNull(key, value);
         valueList.add(value);
       }
       return this;
     }

     /**
      * Stores an array of values with the same key in the built multimap.
      *
      * @throws NullPointerException if the key or any value is null. The builder
      *     is left in an invalid state.
      */
     public Builder<K, V> putAll(K key, V... values) {
       return putAll(key, Arrays.asList(values));
     }

     /**
      * Stores another multimap's entries in the built multimap. The generated
      * multimap's key and value orderings correspond to the iteration ordering
      * of the {@code multimap.asMap()} view, with new keys and values following
      * any existing keys and values.
      *
      * @throws NullPointerException if any key or value in {@code multimap} is
      *     null. The builder is left in an invalid state.
      */
     public Builder<K, V> putAll(Multimap<? extends K, ? extends V> multimap) {
       for (Entry<? extends K, ? extends Collection<? extends V>> entry
           : multimap.asMap().entrySet()) {
         putAll(entry.getKey(), entry.getValue());
       }
       return this;
     }

     /**
      * Specifies the ordering of the generated multimap's keys.
      *
      * @since 8.0
      */
     public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
       this.keyComparator = checkNotNull(keyComparator);
       return this;
     }

     /**
      * Specifies the ordering of the generated multimap's values for each key.
      *
      * @since 8.0
      */
     public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
       this.valueComparator = checkNotNull(valueComparator);
       return this;
     }

     /**
      * Returns a newly-created immutable multimap.
      */
     public ImmutableMultimap<K, V> build() {
       if (valueComparator != null) {
         for (Collection<V> values : builderMultimap.asMap().values()) {
           List<V> list = (List <V>) values;
           Collections.sort(list, valueComparator);
         }
       }
       if (keyComparator != null) {
         Multimap<K, V> sortedCopy = new BuilderMultimap<K, V>();
         List<Map.Entry<K, Collection<V>>> entries = Lists.newArrayList(
             builderMultimap.asMap().entrySet());
         Collections.sort(
             entries,
             Ordering.from(keyComparator).<K>onKeys());
         for (Map.Entry<K, Collection<V>> entry : entries) {
           sortedCopy.putAll(entry.getKey(), entry.getValue());
         }
         builderMultimap = sortedCopy;
       }
       return copyOf(builderMultimap);
     }
   }

   /**
    * Returns an immutable multimap containing the same mappings as {@code
    * multimap}. The generated multimap's key and value orderings correspond to
    * the iteration ordering of the {@code multimap.asMap()} view.
    *
    * <p>Despite the method name, this method attempts to avoid actually copying
    * the data when it is safe to do so. The exact circumstances under which a
    * copy will or will not be performed are undocumented and subject to change.
    *
    * @throws NullPointerException if any key or value in {@code multimap} is
    *         null
    */
   public static <K, V> ImmutableMultimap<K, V> copyOf(
       Multimap<? extends K, ? extends V> multimap) {
     if (multimap instanceof ImmutableMultimap) {
       @SuppressWarnings("unchecked") // safe since multimap is not writable
       ImmutableMultimap<K, V> kvMultimap
           = (ImmutableMultimap<K, V>) multimap;
       if (!kvMultimap.isPartialView()) {
         return kvMultimap;
       }
     }
     return ImmutableListMultimap.copyOf(multimap);
   }

   final transient ImmutableMap<K, ? extends ImmutableCollection<V>> map;
   final transient int size;

   // These constants allow the deserialization code to set final fields. This
   // holder class makes sure they are not initialized unless an instance is
   // deserialized.

   ImmutableMultimap(ImmutableMap<K, ? extends ImmutableCollection<V>> map,
       int size) {
     this.map = map;
     this.size = size;
   }

   // mutators (not supported)

   /**
    * Guaranteed to throw an exception and leave the multimap unmodified.
    *
    * @throws UnsupportedOperationException always
    * @deprecated Unsupported operation.
    */
   @Deprecated
   @Override
   public ImmutableCollection<V> removeAll(Object key) {
     throw new UnsupportedOperationException();
   }

   /**
    * Guaranteed to throw an exception and leave the multimap unmodified.
    *
    * @throws UnsupportedOperationException always
    * @deprecated Unsupported operation.
    */
   @Deprecated
   @Override
   public ImmutableCollection<V> replaceValues(K key,
       Iterable<? extends V> values) {
     throw new UnsupportedOperationException();
   }

   /**
    * Guaranteed to throw an exception and leave the multimap unmodified.
    *
    * @throws UnsupportedOperationException always
    * @deprecated Unsupported operation.
    */
   @Deprecated
   @Override
   public void clear() {
     throw new UnsupportedOperationException();
   }

   /**
    * Returns an immutable collection of the values for the given key.  If no
    * mappings in the multimap have the provided key, an empty immutable
    * collection is returned. The values are in the same order as the parameters
    * used to build this multimap.
    */
   @Override
   public abstract ImmutableCollection<V> get(K key);

   /**
    * Returns an immutable multimap which is the inverse of this one. For every
    * key-value mapping in the original, the result will have a mapping with
    * key and value reversed.
    *
    * @since 11.0
    */
   public abstract ImmutableMultimap<V, K> inverse();

   /**
    * Guaranteed to throw an exception and leave the multimap unmodified.
    *
    * @throws UnsupportedOperationException always
    * @deprecated Unsupported operation.
    */
   @Deprecated
   @Override
   public boolean put(K key, V value) {
     throw new UnsupportedOperationException();
   }

   /**
    * Guaranteed to throw an exception and leave the multimap unmodified.
    *
    * @throws UnsupportedOperationException always
    * @deprecated Unsupported operation.
    */
   @Deprecated
   @Override
   public boolean putAll(K key, Iterable<? extends V> values) {
     throw new UnsupportedOperationException();
   }

   /**
    * Guaranteed to throw an exception and leave the multimap unmodified.
    *
    * @throws UnsupportedOperationException always
    * @deprecated Unsupported operation.
    */
   @Deprecated
   @Override
   public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
     throw new UnsupportedOperationException();
   }

   /**
    * Guaranteed to throw an exception and leave the multimap unmodified.
    *
    * @throws UnsupportedOperationException always
    * @deprecated Unsupported operation.
    */
   @Deprecated
   @Override
   public boolean remove(Object key, Object value) {
     throw new UnsupportedOperationException();
   }

   /**
    * Returns {@code true} if this immutable multimap's implementation contains references to
    * user-created objects that aren't accessible via this multimap's methods. This is generally
    * used to determine whether {@code copyOf} implementations should make an explicit copy to avoid
    * memory leaks.
    */
   boolean isPartialView() {
     return map.isPartialView();
   }

   // accessors

   @Override
   public boolean containsKey(@Nullable Object key) {
     return map.containsKey(key);
   }

   @Override
   public boolean containsValue(@Nullable Object value) {
     return value != null && super.containsValue(value);
   }

   @Override
   public int size() {
     return size;
   }

   // views

   /**
    * Returns an immutable set of the distinct keys in this multimap. These keys
    * are ordered according to when they first appeared during the construction
    * of this multimap.
    */
   @Override
   public ImmutableSet<K> keySet() {
     return map.keySet();
   }

   /**
    * Returns an immutable map that associates each key with its corresponding
    * values in the multimap.
    */
   @Override
   @SuppressWarnings("unchecked") // a widening cast
   public ImmutableMap<K, Collection<V>> asMap() {
     return (ImmutableMap) map;
   }

   @Override
   Map<K, Collection<V>> createAsMap() {
     throw new AssertionError("should never be called");
   }

   /**
    * Returns an immutable collection of all key-value pairs in the multimap. Its
    * iterator traverses the values for the first key, the values for the second
    * key, and so on.
    */
   @Override
   public ImmutableCollection<Entry<K, V>> entries() {
     return (ImmutableCollection<Entry<K, V>>) super.entries();
   }

   @Override
   ImmutableCollection<Entry<K, V>> createEntries() {
     return new EntryCollection<K, V>(this);
   }

   private static class EntryCollection<K, V>
       extends ImmutableCollection<Entry<K, V>> {
     final ImmutableMultimap<K, V> multimap;

     EntryCollection(ImmutableMultimap<K, V> multimap) {
       this.multimap = multimap;
     }

     @Override public UnmodifiableIterator<Entry<K, V>> iterator() {
       return multimap.entryIterator();
     }

     @Override boolean isPartialView() {
       return multimap.isPartialView();
     }

     @Override
     public int size() {
       return multimap.size();
     }

     @Override public boolean contains(Object object) {
       if (object instanceof Entry) {
         Entry<?, ?> entry = (Entry<?, ?>) object;
         return multimap.containsEntry(entry.getKey(), entry.getValue());
       }
       return false;
     }

     private static final long serialVersionUID = 0;
   }

   private abstract class Itr<T> extends UnmodifiableIterator<T> {
     final Iterator<Entry<K, Collection<V>>> mapIterator = asMap().entrySet().iterator();
     K key = null;
     Iterator<V> valueIterator = Iterators.emptyIterator();

     abstract T output(K key, V value);

     @Override
     public boolean hasNext() {
       return mapIterator.hasNext() || valueIterator.hasNext();
     }

     @Override
     public T next() {
       if (!valueIterator.hasNext()) {
         Entry<K, Collection<V>> mapEntry = mapIterator.next();
         key = mapEntry.getKey();
         valueIterator = mapEntry.getValue().iterator();
       }
       return output(key, valueIterator.next());
     }
   }

   @Override
   UnmodifiableIterator<Entry<K, V>> entryIterator() {
     return new Itr<Entry<K, V>>() {
       @Override
       Entry<K, V> output(K key, V value) {
         return Maps.immutableEntry(key, value);
       }
     };
   }

   /**
    * Returns a collection, which may contain duplicates, of all keys. The number
    * of times a key appears in the returned multiset equals the number of
    * mappings the key has in the multimap. Duplicate keys appear consecutively
    * in the multiset's iteration order.
    */
   @Override
   public ImmutableMultiset<K> keys() {
     return (ImmutableMultiset<K>) super.keys();
   }

   @Override
   ImmutableMultiset<K> createKeys() {
     return new Keys();
   }

   @SuppressWarnings("serial") // Uses writeReplace, not default serialization
   class Keys extends ImmutableMultiset<K> {
     @Override
     public boolean contains(@Nullable Object object) {
       return containsKey(object);
     }

     @Override
     public int count(@Nullable Object element) {
       Collection<V> values = map.get(element);
       return (values == null) ? 0 : values.size();
     }

     @Override
     public Set<K> elementSet() {
       return keySet();
     }

     @Override
     public int size() {
       return ImmutableMultimap.this.size();
     }

     @Override
     Multiset.Entry<K> getEntry(int index) {
       Map.Entry<K, ? extends Collection<V>> entry = map.entrySet().asList().get(index);
       return Multisets.immutableEntry(entry.getKey(), entry.getValue().size());
     }

     @Override
     boolean isPartialView() {
       return true;
     }
   }

   /**
    * Returns an immutable collection of the values in this multimap. Its
    * iterator traverses the values for the first key, the values for the second
    * key, and so on.
    */
   @Override
   public ImmutableCollection<V> values() {
     return (ImmutableCollection<V>) super.values();
   }

   @Override
   ImmutableCollection<V> createValues() {
     return new Values<K, V>(this);
   }

   @Override
   UnmodifiableIterator<V> valueIterator() {
     return new Itr<V>() {
       @Override
       V output(K key, V value) {
         return value;
       }
     };
   }

   private static final class Values<K, V> extends ImmutableCollection<V> {
     private transient final ImmutableMultimap<K, V> multimap;

     Values(ImmutableMultimap<K, V> multimap) {
       this.multimap = multimap;
     }

     @Override
     public boolean contains(@Nullable Object object) {
       return multimap.containsValue(object);
     }

     @Override public UnmodifiableIterator<V> iterator() {
       return multimap.valueIterator();
     }

     @Override
     public int size() {
       return multimap.size();
     }

     @Override boolean isPartialView() {
       return true;
     }

     private static final long serialVersionUID = 0;
   }

   private static final long serialVersionUID = 0;
 }
	/*
	* Copyright (C) 2008 The Guava Authors
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.google.common.collect;

	import static com.google.common.base.Preconditions.checkNotNull;
	import static com.google.common.collect.CollectPreconditions.checkEntryNotNull;

	import com.google.common.annotations.GwtCompatible;

	import java.io.Serializable;
	import java.util.Arrays;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.Iterator;
	import java.util.LinkedHashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Map.Entry;
	import java.util.Set;

	import javax.annotation.Nullable;

	/**
	* An immutable {@link Multimap}. Does not permit null keys or values.
	*
	* <p>Unlike {@link Multimaps#unmodifiableMultimap(Multimap)}, which is
	* a <i>view</i> of a separate multimap which can still change, an instance of
	* {@code ImmutableMultimap} contains its own data and will <i>never</i>
	* change. {@code ImmutableMultimap} is convenient for
	* {@code public static final} multimaps ("constant multimaps") and also lets
	* you easily make a "defensive copy" of a multimap provided to your class by
	* a caller.
	*
	* <p><b>Note:</b> Although this class is not final, it cannot be subclassed as
	* it has no public or protected constructors. Thus, instances of this class
	* are guaranteed to be immutable.
	*
	* <p>In addition to methods defined by {@link Multimap}, an {@link #inverse}
	* method is also supported.
	*
	* <p>See the Guava User Guide article on <a href=
	* "http://code.google.com/p/guava-libraries/wiki/ImmutableCollectionsExplained">
	* immutable collections</a>.
	*
	* @author Jared Levy
	* @since 2.0 (imported from Google Collections Library)
	*/
	@GwtCompatible(emulated = true)
	public abstract class ImmutableMultimap<K, V> extends AbstractMultimap<K, V>
	implements Serializable {

	/** Returns an empty multimap. */
	public static <K, V> ImmutableMultimap<K, V> of() {
	return ImmutableListMultimap.of();
	}

	/**
	* Returns an immutable multimap containing a single entry.
	*/
	public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1) {
	return ImmutableListMultimap.of(k1, v1);
	}

	/**
	* Returns an immutable multimap containing the given entries, in order.
	*/
	public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1, K k2, V v2) {
	return ImmutableListMultimap.of(k1, v1, k2, v2);
	}

	/**
	* Returns an immutable multimap containing the given entries, in order.
	*/
	public static <K, V> ImmutableMultimap<K, V> of(
	K k1, V v1, K k2, V v2, K k3, V v3) {
	return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3);
	}

	/**
	* Returns an immutable multimap containing the given entries, in order.
	*/
	public static <K, V> ImmutableMultimap<K, V> of(
	K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
	return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3, k4, v4);
	}

	/**
	* Returns an immutable multimap containing the given entries, in order.
	*/
	public static <K, V> ImmutableMultimap<K, V> of(
	K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
	return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5);
	}

	// looking for of() with > 5 entries? Use the builder instead.

	/**
	* Returns a new builder. The generated builder is equivalent to the builder
	* created by the {@link Builder} constructor.
	*/
	public static <K, V> Builder<K, V> builder() {
	return new Builder<K, V>();
	}

	/**
	* Multimap for {@link ImmutableMultimap.Builder} that maintains key and
	* value orderings, allows duplicate values, and performs better than
	* {@link LinkedListMultimap}.
	*/
	private static class BuilderMultimap<K, V> extends AbstractMapBasedMultimap<K, V> {
	BuilderMultimap() {
	super(new LinkedHashMap<K, Collection<V>>());
	}
	@Override Collection<V> createCollection() {
	return Lists.newArrayList();
	}
	private static final long serialVersionUID = 0;
	}

	/**
	* A builder for creating immutable multimap instances, especially
	* {@code public static final} multimaps ("constant multimaps"). Example:
	* <pre> {@code
	*
	* static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
	* new ImmutableMultimap.Builder<String, Integer>()
	* .put("one", 1)
	* .putAll("several", 1, 2, 3)
	* .putAll("many", 1, 2, 3, 4, 5)
	* .build();}</pre>
	*
	* <p>Builder instances can be reused; it is safe to call {@link #build} multiple
	* times to build multiple multimaps in series. Each multimap contains the
	* key-value mappings in the previously created multimaps.
	*
	* @since 2.0 (imported from Google Collections Library)
	*/
	public static class Builder<K, V> {
	Multimap<K, V> builderMultimap = new BuilderMultimap<K, V>();
	Comparator<? super K> keyComparator;
	Comparator<? super V> valueComparator;

	/**
	* Creates a new builder. The returned builder is equivalent to the builder
	* generated by {@link ImmutableMultimap#builder}.
	*/
	public Builder() {}

	/**
	* Adds a key-value mapping to the built multimap.
	*/
	public Builder<K, V> put(K key, V value) {
	checkEntryNotNull(key, value);
	builderMultimap.put(key, value);
	return this;
	}

	/**
	* Adds an entry to the built multimap.
	*
	* @since 11.0
	*/
	public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
	return put(entry.getKey(), entry.getValue());
	}

	/**
	* Stores a collection of values with the same key in the built multimap.
	*
	* @throws NullPointerException if {@code key}, {@code values}, or any
	* element in {@code values} is null. The builder is left in an invalid
	* state.
	*/
	public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
	if (key == null) {
	throw new NullPointerException(
	"null key in entry: null=" + Iterables.toString(values));
	}
	Collection<V> valueList = builderMultimap.get(key);
	for (V value : values) {
	checkEntryNotNull(key, value);
	valueList.add(value);
	}
	return this;
	}

	/**
	* Stores an array of values with the same key in the built multimap.
	*
	* @throws NullPointerException if the key or any value is null. The builder
	* is left in an invalid state.
	*/
	public Builder<K, V> putAll(K key, V... values) {
	return putAll(key, Arrays.asList(values));
	}

	/**
	* Stores another multimap's entries in the built multimap. The generated
	* multimap's key and value orderings correspond to the iteration ordering
	* of the {@code multimap.asMap()} view, with new keys and values following
	* any existing keys and values.
	*
	* @throws NullPointerException if any key or value in {@code multimap} is
	* null. The builder is left in an invalid state.
	*/
	public Builder<K, V> putAll(Multimap<? extends K, ? extends V> multimap) {
	for (Entry<? extends K, ? extends Collection<? extends V>> entry
	: multimap.asMap().entrySet()) {
	putAll(entry.getKey(), entry.getValue());
	}
	return this;
	}

	/**
	* Specifies the ordering of the generated multimap's keys.
	*
	* @since 8.0
	*/
	public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
	this.keyComparator = checkNotNull(keyComparator);
	return this;
	}

	/**
	* Specifies the ordering of the generated multimap's values for each key.
	*
	* @since 8.0
	*/
	public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
	this.valueComparator = checkNotNull(valueComparator);
	return this;
	}

	/**
	* Returns a newly-created immutable multimap.
	*/
	public ImmutableMultimap<K, V> build() {
	if (valueComparator != null) {
	for (Collection<V> values : builderMultimap.asMap().values()) {
	List<V> list = (List <V>) values;
	Collections.sort(list, valueComparator);
	}
	}
	if (keyComparator != null) {
	Multimap<K, V> sortedCopy = new BuilderMultimap<K, V>();
	List<Map.Entry<K, Collection<V>>> entries = Lists.newArrayList(
	builderMultimap.asMap().entrySet());
	Collections.sort(
	entries,
	Ordering.from(keyComparator).<K>onKeys());
	for (Map.Entry<K, Collection<V>> entry : entries) {
	sortedCopy.putAll(entry.getKey(), entry.getValue());
	}
	builderMultimap = sortedCopy;
	}
	return copyOf(builderMultimap);
	}
	}

	/**
	* Returns an immutable multimap containing the same mappings as {@code
	* multimap}. The generated multimap's key and value orderings correspond to
	* the iteration ordering of the {@code multimap.asMap()} view.
	*
	* <p>Despite the method name, this method attempts to avoid actually copying
	* the data when it is safe to do so. The exact circumstances under which a
	* copy will or will not be performed are undocumented and subject to change.
	*
	* @throws NullPointerException if any key or value in {@code multimap} is
	* null
	*/
	public static <K, V> ImmutableMultimap<K, V> copyOf(
	Multimap<? extends K, ? extends V> multimap) {
	if (multimap instanceof ImmutableMultimap) {
	@SuppressWarnings("unchecked") // safe since multimap is not writable
	ImmutableMultimap<K, V> kvMultimap
	= (ImmutableMultimap<K, V>) multimap;
	if (!kvMultimap.isPartialView()) {
	return kvMultimap;
	}
	}
	return ImmutableListMultimap.copyOf(multimap);
	}

	final transient ImmutableMap<K, ? extends ImmutableCollection<V>> map;
	final transient int size;

	// These constants allow the deserialization code to set final fields. This
	// holder class makes sure they are not initialized unless an instance is
	// deserialized.

	ImmutableMultimap(ImmutableMap<K, ? extends ImmutableCollection<V>> map,
	int size) {
	this.map = map;
	this.size = size;
	}

	// mutators (not supported)

	/**
	* Guaranteed to throw an exception and leave the multimap unmodified.
	*
	* @throws UnsupportedOperationException always
	* @deprecated Unsupported operation.
	*/
	@Deprecated
	@Override
	public ImmutableCollection<V> removeAll(Object key) {
	throw new UnsupportedOperationException();
	}

	/**
	* Guaranteed to throw an exception and leave the multimap unmodified.
	*
	* @throws UnsupportedOperationException always
	* @deprecated Unsupported operation.
	*/
	@Deprecated
	@Override
	public ImmutableCollection<V> replaceValues(K key,
	Iterable<? extends V> values) {
	throw new UnsupportedOperationException();
	}

	/**
	* Guaranteed to throw an exception and leave the multimap unmodified.
	*
	* @throws UnsupportedOperationException always
	* @deprecated Unsupported operation.
	*/
	@Deprecated
	@Override
	public void clear() {
	throw new UnsupportedOperationException();
	}

	/**
	* Returns an immutable collection of the values for the given key. If no
	* mappings in the multimap have the provided key, an empty immutable
	* collection is returned. The values are in the same order as the parameters
	* used to build this multimap.
	*/
	@Override
	public abstract ImmutableCollection<V> get(K key);

	/**
	* Returns an immutable multimap which is the inverse of this one. For every
	* key-value mapping in the original, the result will have a mapping with
	* key and value reversed.
	*
	* @since 11.0
	*/
	public abstract ImmutableMultimap<V, K> inverse();

	/**
	* Guaranteed to throw an exception and leave the multimap unmodified.
	*
	* @throws UnsupportedOperationException always
	* @deprecated Unsupported operation.
	*/
	@Deprecated
	@Override
	public boolean put(K key, V value) {
	throw new UnsupportedOperationException();
	}

	/**
	* Guaranteed to throw an exception and leave the multimap unmodified.
	*
	* @throws UnsupportedOperationException always
	* @deprecated Unsupported operation.
	*/
	@Deprecated
	@Override
	public boolean putAll(K key, Iterable<? extends V> values) {
	throw new UnsupportedOperationException();
	}

	/**
	* Guaranteed to throw an exception and leave the multimap unmodified.
	*
	* @throws UnsupportedOperationException always
	* @deprecated Unsupported operation.
	*/
	@Deprecated
	@Override
	public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
	throw new UnsupportedOperationException();
	}

	/**
	* Guaranteed to throw an exception and leave the multimap unmodified.
	*
	* @throws UnsupportedOperationException always
	* @deprecated Unsupported operation.
	*/
	@Deprecated
	@Override
	public boolean remove(Object key, Object value) {
	throw new UnsupportedOperationException();
	}

	/**
	* Returns {@code true} if this immutable multimap's implementation contains references to
	* user-created objects that aren't accessible via this multimap's methods. This is generally
	* used to determine whether {@code copyOf} implementations should make an explicit copy to avoid
	* memory leaks.
	*/
	boolean isPartialView() {
	return map.isPartialView();
	}

	// accessors

	@Override
	public boolean containsKey(@Nullable Object key) {
	return map.containsKey(key);
	}

	@Override
	public boolean containsValue(@Nullable Object value) {
	return value != null && super.containsValue(value);
	}

	@Override
	public int size() {
	return size;
	}

	// views

	/**
	* Returns an immutable set of the distinct keys in this multimap. These keys
	* are ordered according to when they first appeared during the construction
	* of this multimap.
	*/
	@Override
	public ImmutableSet<K> keySet() {
	return map.keySet();
	}

	/**
	* Returns an immutable map that associates each key with its corresponding
	* values in the multimap.
	*/
	@Override
	@SuppressWarnings("unchecked") // a widening cast
	public ImmutableMap<K, Collection<V>> asMap() {
	return (ImmutableMap) map;
	}

	@Override
	Map<K, Collection<V>> createAsMap() {
	throw new AssertionError("should never be called");
	}

	/**
	* Returns an immutable collection of all key-value pairs in the multimap. Its
	* iterator traverses the values for the first key, the values for the second
	* key, and so on.
	*/
	@Override
	public ImmutableCollection<Entry<K, V>> entries() {
	return (ImmutableCollection<Entry<K, V>>) super.entries();
	}

	@Override
	ImmutableCollection<Entry<K, V>> createEntries() {
	return new EntryCollection<K, V>(this);
	}

	private static class EntryCollection<K, V>
	extends ImmutableCollection<Entry<K, V>> {
	final ImmutableMultimap<K, V> multimap;

	EntryCollection(ImmutableMultimap<K, V> multimap) {
	this.multimap = multimap;
	}

	@Override public UnmodifiableIterator<Entry<K, V>> iterator() {
	return multimap.entryIterator();
	}

	@Override boolean isPartialView() {
	return multimap.isPartialView();
	}

	@Override
	public int size() {
	return multimap.size();
	}

	@Override public boolean contains(Object object) {
	if (object instanceof Entry) {
	Entry<?, ?> entry = (Entry<?, ?>) object;
	return multimap.containsEntry(entry.getKey(), entry.getValue());
	}
	return false;
	}

	private static final long serialVersionUID = 0;
	}

	private abstract class Itr<T> extends UnmodifiableIterator<T> {
	final Iterator<Entry<K, Collection<V>>> mapIterator = asMap().entrySet().iterator();
	K key = null;
	Iterator<V> valueIterator = Iterators.emptyIterator();

	abstract T output(K key, V value);

	@Override
	public boolean hasNext() {
	return mapIterator.hasNext() \|\| valueIterator.hasNext();
	}

	@Override
	public T next() {
	if (!valueIterator.hasNext()) {
	Entry<K, Collection<V>> mapEntry = mapIterator.next();
	key = mapEntry.getKey();
	valueIterator = mapEntry.getValue().iterator();
	}
	return output(key, valueIterator.next());
	}
	}

	@Override
	UnmodifiableIterator<Entry<K, V>> entryIterator() {
	return new Itr<Entry<K, V>>() {
	@Override
	Entry<K, V> output(K key, V value) {
	return Maps.immutableEntry(key, value);
	}
	};
	}

	/**
	* Returns a collection, which may contain duplicates, of all keys. The number
	* of times a key appears in the returned multiset equals the number of
	* mappings the key has in the multimap. Duplicate keys appear consecutively
	* in the multiset's iteration order.
	*/
	@Override
	public ImmutableMultiset<K> keys() {
	return (ImmutableMultiset<K>) super.keys();
	}

	@Override
	ImmutableMultiset<K> createKeys() {
	return new Keys();
	}

	@SuppressWarnings("serial") // Uses writeReplace, not default serialization
	class Keys extends ImmutableMultiset<K> {
	@Override
	public boolean contains(@Nullable Object object) {
	return containsKey(object);
	}

	@Override
	public int count(@Nullable Object element) {
	Collection<V> values = map.get(element);
	return (values == null) ? 0 : values.size();
	}

	@Override
	public Set<K> elementSet() {
	return keySet();
	}

	@Override
	public int size() {
	return ImmutableMultimap.this.size();
	}

	@Override
	Multiset.Entry<K> getEntry(int index) {
	Map.Entry<K, ? extends Collection<V>> entry = map.entrySet().asList().get(index);
	return Multisets.immutableEntry(entry.getKey(), entry.getValue().size());
	}

	@Override
	boolean isPartialView() {
	return true;
	}
	}

	/**
	* Returns an immutable collection of the values in this multimap. Its
	* iterator traverses the values for the first key, the values for the second
	* key, and so on.
	*/
	@Override
	public ImmutableCollection<V> values() {
	return (ImmutableCollection<V>) super.values();
	}

	@Override
	ImmutableCollection<V> createValues() {
	return new Values<K, V>(this);
	}

	@Override
	UnmodifiableIterator<V> valueIterator() {
	return new Itr<V>() {
	@Override
	V output(K key, V value) {
	return value;
	}
	};
	}

	private static final class Values<K, V> extends ImmutableCollection<V> {
	private transient final ImmutableMultimap<K, V> multimap;

	Values(ImmutableMultimap<K, V> multimap) {
	this.multimap = multimap;
	}

	@Override
	public boolean contains(@Nullable Object object) {
	return multimap.containsValue(object);
	}

	@Override public UnmodifiableIterator<V> iterator() {
	return multimap.valueIterator();
	}

	@Override
	public int size() {
	return multimap.size();
	}

	@Override boolean isPartialView() {
	return true;
	}

	private static final long serialVersionUID = 0;
	}

	private static final long serialVersionUID = 0;
	}