src/com/google/common/collect/ImmutableMultiset.java - platform/external/guava - Git at Google

 /*
  * Copyright (C) 2008 Google Inc.
  *
  * 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 com.google.common.annotations.GwtCompatible;
 import static com.google.common.base.Preconditions.checkNotNull;
 import com.google.common.collect.Serialization.FieldSetter;

 import java.io.IOException;
 import java.io.InvalidObjectException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.util.Arrays;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;

 import javax.annotation.Nullable;

 /**
  * An immutable hash-based multiset. Does not permit null elements.
  *
  * <p>Its iterator orders elements according to the first appearance of the
  * element among the items passed to the factory method or builder. When the
  * multiset contains multiple instances of an element, those instances are
  * consecutive in the iteration order.
  *
  * @author Jared Levy
  * @since 2010.01.04 <b>stable</b> (imported from Google Collections Library)
  */
 @GwtCompatible(serializable = true)
 public class ImmutableMultiset<E> extends ImmutableCollection<E>
     implements Multiset<E> {

   /**
    * Returns the empty immutable multiset.
    */
   @SuppressWarnings("unchecked") // all supported methods are covariant
   public static <E> ImmutableMultiset<E> of() {
     // BEGIN android-changed
     return (ImmutableMultiset) EmptyImmutableMultiset.INSTANCE;
     // END android-changed
   }

   /**
    * Returns an immutable multiset containing the given elements.
    *
    * <p>The multiset is ordered by the first occurrence of each element. For
    * example, {@code ImmutableMultiset.of(2, 3, 1, 3)} yields a multiset with
    * elements in the order {@code 2, 3, 3, 1}.
    *
    * @throws NullPointerException if any of {@code elements} is null
    */
   public static <E> ImmutableMultiset<E> of(E... elements) {
     return copyOf(Arrays.asList(elements));
   }

   /**
    * Returns an immutable multiset containing the given elements.
    *
    * <p>The multiset is ordered by the first occurrence of each element. For
    * example, {@code ImmutableMultiset.copyOf(Arrays.asList(2, 3, 1, 3))} yields
    * a multiset with elements in the order {@code 2, 3, 3, 1}.
    *
    * <p>Note that if {@code c} is a {@code Collection<String>}, then {@code
    * ImmutableMultiset.copyOf(c)} returns an {@code ImmutableMultiset<String>}
    * containing each of the strings in {@code c}, while
    * {@code ImmutableMultiset.of(c)} returns an
    * {@code ImmutableMultiset<Collection<String>>} containing one element (the
    * given collection itself).
    *
    * <p><b>Note:</b> Despite what the method name suggests, if {@code elements}
    * is an {@code ImmutableMultiset}, no copy will actually be performed, and
    * the given multiset itself will be returned.
    *
    * @throws NullPointerException if any of {@code elements} is null
    */
   public static <E> ImmutableMultiset<E> copyOf(
       Iterable<? extends E> elements) {
     if (elements instanceof ImmutableMultiset) {
       @SuppressWarnings("unchecked") // all supported methods are covariant
       ImmutableMultiset<E> result = (ImmutableMultiset<E>) elements;
       return result;
     }

     @SuppressWarnings("unchecked") // the cast causes a warning
     Multiset<? extends E> multiset = (elements instanceof Multiset)
         ? (Multiset<? extends E>) elements
         : LinkedHashMultiset.create(elements);

     return copyOfInternal(multiset);
   }

   private static <E> ImmutableMultiset<E> copyOfInternal(
       Multiset<? extends E> multiset) {
     long size = 0;
     ImmutableMap.Builder<E, Integer> builder = ImmutableMap.builder();

     for (Entry<? extends E> entry : multiset.entrySet()) {
       int count = entry.getCount();
       if (count > 0) {
         // Since ImmutableMap.Builder throws an NPE if an element is null, no
         // other null checks are needed.
         builder.put(entry.getElement(), count);
         size += count;
       }
     }

     if (size == 0) {
       return of();
     }
     return new ImmutableMultiset<E>(
         builder.build(), (int) Math.min(size, Integer.MAX_VALUE));
   }

   /**
    * Returns an immutable multiset containing the given elements.
    *
    * <p>The multiset is ordered by the first occurrence of each element. For
    * example,
    * {@code ImmutableMultiset.copyOf(Arrays.asList(2, 3, 1, 3).iterator())}
    * yields a multiset with elements in the order {@code 2, 3, 3, 1}.
    *
    * @throws NullPointerException if any of {@code elements} is null
    */
   public static <E> ImmutableMultiset<E> copyOf(
       Iterator<? extends E> elements) {
     Multiset<E> multiset = LinkedHashMultiset.create();
     Iterators.addAll(multiset, elements);
     return copyOfInternal(multiset);
   }

   private final transient ImmutableMap<E, Integer> map;
   private 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.
   @SuppressWarnings("unchecked")
   // eclipse doesn't like the raw types here, but they're harmless
   private static class FieldSettersHolder {
     static final FieldSetter<ImmutableMultiset> MAP_FIELD_SETTER
         = Serialization.getFieldSetter(ImmutableMultiset.class, "map");
     static final FieldSetter<ImmutableMultiset> SIZE_FIELD_SETTER
         = Serialization.getFieldSetter(ImmutableMultiset.class, "size");
   }

   ImmutableMultiset(ImmutableMap<E, Integer> map, int size) {
     this.map = map;
     this.size = size;
   }

   public int count(@Nullable Object element) {
     Integer value = map.get(element);
     return (value == null) ? 0 : value;
   }

   @Override public UnmodifiableIterator<E> iterator() {
     final Iterator<Map.Entry<E, Integer>> mapIterator
         = map.entrySet().iterator();

     return new UnmodifiableIterator<E>() {
       int remaining;
       E element;

       public boolean hasNext() {
         return (remaining > 0) || mapIterator.hasNext();
       }

       public E next() {
         if (remaining <= 0) {
           Map.Entry<E, Integer> entry = mapIterator.next();
           element = entry.getKey();
           remaining = entry.getValue();
         }
         remaining--;
         return element;
       }
     };
   }

   public int size() {
     return size;
   }

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

   /**
    * Guaranteed to throw an exception and leave the collection unmodified.
    *
    * @throws UnsupportedOperationException always
    */
   public int add(E element, int occurrences) {
     throw new UnsupportedOperationException();
   }

   /**
    * Guaranteed to throw an exception and leave the collection unmodified.
    *
    * @throws UnsupportedOperationException always
    */
   public int remove(Object element, int occurrences) {
     throw new UnsupportedOperationException();
   }

   /**
    * Guaranteed to throw an exception and leave the collection unmodified.
    *
    * @throws UnsupportedOperationException always
    */
   public int setCount(E element, int count) {
     throw new UnsupportedOperationException();
   }

   /**
    * Guaranteed to throw an exception and leave the collection unmodified.
    *
    * @throws UnsupportedOperationException always
    */
   public boolean setCount(E element, int oldCount, int newCount) {
     throw new UnsupportedOperationException();
   }

   @Override public boolean equals(@Nullable Object object) {
     if (object == this) {
       return true;
     }
     if (object instanceof Multiset) {
       Multiset<?> that = (Multiset<?>) object;
       if (this.size() != that.size()) {
         return false;
       }
       for (Entry<?> entry : that.entrySet()) {
         if (count(entry.getElement()) != entry.getCount()) {
           return false;
         }
       }
       return true;
     }
     return false;
   }

   @Override public int hashCode() {
     // could cache this, but not considered worthwhile to do so
     return map.hashCode();
   }

   @Override public String toString() {
     return entrySet().toString();
   }

   // TODO: Serialization of the element set should serialize the multiset, and
   // deserialization should call multiset.elementSet(). Then
   // reserialized(multiset).elementSet() == reserialized(multiset.elementSet())
   // Currently, those object references differ.
   public Set<E> elementSet() {
     return map.keySet();
   }

   private transient ImmutableSet<Entry<E>> entrySet;

   public Set<Entry<E>> entrySet() {
     ImmutableSet<Entry<E>> es = entrySet;
     return (es == null) ? (entrySet = new EntrySet<E>(this)) : es;
   }

   private static class EntrySet<E> extends ImmutableSet<Entry<E>> {
     final ImmutableMultiset<E> multiset;

     public EntrySet(ImmutableMultiset<E> multiset) {
       this.multiset = multiset;
     }

     @Override public UnmodifiableIterator<Entry<E>> iterator() {
       final Iterator<Map.Entry<E, Integer>> mapIterator
           = multiset.map.entrySet().iterator();
       return new UnmodifiableIterator<Entry<E>>() {
         public boolean hasNext() {
           return mapIterator.hasNext();
         }
         public Entry<E> next() {
           Map.Entry<E, Integer> mapEntry = mapIterator.next();
           return
               Multisets.immutableEntry(mapEntry.getKey(), mapEntry.getValue());
         }
       };
     }

     public int size() {
       return multiset.map.size();
     }

     @Override public boolean contains(Object o) {
       if (o instanceof Entry) {
         Entry<?> entry = (Entry<?>) o;
         if (entry.getCount() <= 0) {
           return false;
         }
         int count = multiset.count(entry.getElement());
         return count == entry.getCount();
       }
       return false;
     }

     @Override public int hashCode() {
       return multiset.map.hashCode();
     }

     @Override Object writeReplace() {
       return this;
     }

     private static final long serialVersionUID = 0;
   }

   /**
    * @serialData the number of distinct elements, the first element, its count,
    *     the second element, its count, and so on
    */
   private void writeObject(ObjectOutputStream stream) throws IOException {
     stream.defaultWriteObject();
     Serialization.writeMultiset(this, stream);
   }

   private void readObject(ObjectInputStream stream)
       throws IOException, ClassNotFoundException {
     stream.defaultReadObject();
     int entryCount = stream.readInt();
     ImmutableMap.Builder<E, Integer> builder = ImmutableMap.builder();
     long tmpSize = 0;
     for (int i = 0; i < entryCount; i++) {
       @SuppressWarnings("unchecked") // reading data stored by writeMultiset
       E element = (E) stream.readObject();
       int count = stream.readInt();
       if (count <= 0) {
         throw new InvalidObjectException("Invalid count " + count);
       }
       builder.put(element, count);
       tmpSize += count;
     }

     FieldSettersHolder.MAP_FIELD_SETTER.set(this, builder.build());
     FieldSettersHolder.SIZE_FIELD_SETTER.set(
         this, (int) Math.min(tmpSize, Integer.MAX_VALUE));
   }

   @Override Object writeReplace() {
     return this;
   }

   private static final long serialVersionUID = 0;

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

   /**
    * A builder for creating immutable multiset instances, especially
    * {@code public static final} multisets ("constant multisets").
    *
    * <p>Example:
    * <pre>   {@code
    *   public static final ImmutableMultiset<Bean> BEANS
    *       = new ImmutableMultiset.Builder<Bean>()
    *           .addCopies(Bean.COCOA, 4)
    *           .addCopies(Bean.GARDEN, 6)
    *           .addCopies(Bean.RED, 8)
    *           .addCopies(Bean.BLACK_EYED, 10)
    *           .build();}</pre>
    *
    * <p>Builder instances can be reused - it is safe to call {@link #build}
    * multiple times to build multiple multisets in series. Each multiset
    * is a superset of the multiset created before it.
    */
   public static final class Builder<E> extends ImmutableCollection.Builder<E> {
     private final Multiset<E> contents = LinkedHashMultiset.create();

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

     /**
      * Adds {@code element} to the {@code ImmutableMultiset}.
      *
      * @param element the element to add
      * @return this {@code Builder} object
      * @throws NullPointerException if {@code element} is null
      */
     @Override public Builder<E> add(E element) {
       contents.add(checkNotNull(element));
       return this;
     }

     /**
      * Adds a number of occurrences of an element to this {@code
      * ImmutableMultiset}.
      *
      * @param element the element to add
      * @param occurrences the number of occurrences of the element to add. May
      *     be zero, in which case no change will be made.
      * @return this {@code Builder} object
      * @throws NullPointerException if {@code element} is null
      * @throws IllegalArgumentException if {@code occurrences} is negative, or
      *     if this operation would result in more than {@link Integer#MAX_VALUE}
      *     occurrences of the element
      */
     public Builder<E> addCopies(E element, int occurrences) {
       contents.add(checkNotNull(element), occurrences);
       return this;
     }

     /**
      * Adds or removes the necessary occurrences of an element such that the
      * element attains the desired count.
      *
      * @param element the element to add or remove occurrences of
      * @param count the desired count of the element in this multiset
      * @return this {@code Builder} object
      * @throws NullPointerException if {@code element} is null
      * @throws IllegalArgumentException if {@code count} is negative
      */
     public Builder<E> setCount(E element, int count) {
       contents.setCount(checkNotNull(element), count);
       return this;
     }

     /**
      * Adds each element of {@code elements} to the {@code ImmutableMultiset}.
      *
      * @param elements the elements to add
      * @return this {@code Builder} object
      * @throws NullPointerException if {@code elements} is null or contains a
      *     null element
      */
     @Override public Builder<E> add(E... elements) {
       super.add(elements);
       return this;
     }

     /**
      * Adds each element of {@code elements} to the {@code ImmutableMultiset}.
      *
      * @param elements the {@code Iterable} to add to the {@code
      *     ImmutableMultiset}
      * @return this {@code Builder} object
      * @throws NullPointerException if {@code elements} is null or contains a
      *     null element
      */
     @Override public Builder<E> addAll(Iterable<? extends E> elements) {
       if (elements instanceof Multiset) {
         @SuppressWarnings("unchecked")
         Multiset<? extends E> multiset = (Multiset<? extends E>) elements;
         for (Entry<? extends E> entry : multiset.entrySet()) {
           addCopies(entry.getElement(), entry.getCount());
         }
       } else {
         super.addAll(elements);
       }
       return this;
     }

     /**
      * Adds each element of {@code elements} to the {@code ImmutableMultiset}.
      *
      * @param elements the elements to add to the {@code ImmutableMultiset}
      * @return this {@code Builder} object
      * @throws NullPointerException if {@code elements} is null or contains a
      *     null element
      */
     @Override public Builder<E> addAll(Iterator<? extends E> elements) {
       super.addAll(elements);
       return this;
     }

     /**
      * Returns a newly-created {@code ImmutableMultiset} based on the contents
      * of the {@code Builder}.
      */
     @Override public ImmutableMultiset<E> build() {
       return copyOf(contents);
     }
   }
 }
	/*
	* Copyright (C) 2008 Google Inc.
	*
	* 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 com.google.common.annotations.GwtCompatible;
	import static com.google.common.base.Preconditions.checkNotNull;
	import com.google.common.collect.Serialization.FieldSetter;

	import java.io.IOException;
	import java.io.InvalidObjectException;
	import java.io.ObjectInputStream;
	import java.io.ObjectOutputStream;
	import java.util.Arrays;
	import java.util.Iterator;
	import java.util.Map;
	import java.util.Set;

	import javax.annotation.Nullable;

	/**
	* An immutable hash-based multiset. Does not permit null elements.
	*
	* <p>Its iterator orders elements according to the first appearance of the
	* element among the items passed to the factory method or builder. When the
	* multiset contains multiple instances of an element, those instances are
	* consecutive in the iteration order.
	*
	* @author Jared Levy
	* @since 2010.01.04 <b>stable</b> (imported from Google Collections Library)
	*/
	@GwtCompatible(serializable = true)
	public class ImmutableMultiset<E> extends ImmutableCollection<E>
	implements Multiset<E> {

	/**
	* Returns the empty immutable multiset.
	*/
	@SuppressWarnings("unchecked") // all supported methods are covariant
	public static <E> ImmutableMultiset<E> of() {
	// BEGIN android-changed
	return (ImmutableMultiset) EmptyImmutableMultiset.INSTANCE;
	// END android-changed
	}

	/**
	* Returns an immutable multiset containing the given elements.
	*
	* <p>The multiset is ordered by the first occurrence of each element. For
	* example, {@code ImmutableMultiset.of(2, 3, 1, 3)} yields a multiset with
	* elements in the order {@code 2, 3, 3, 1}.
	*
	* @throws NullPointerException if any of {@code elements} is null
	*/
	public static <E> ImmutableMultiset<E> of(E... elements) {
	return copyOf(Arrays.asList(elements));
	}

	/**
	* Returns an immutable multiset containing the given elements.
	*
	* <p>The multiset is ordered by the first occurrence of each element. For
	* example, {@code ImmutableMultiset.copyOf(Arrays.asList(2, 3, 1, 3))} yields
	* a multiset with elements in the order {@code 2, 3, 3, 1}.
	*
	* <p>Note that if {@code c} is a {@code Collection<String>}, then {@code
	* ImmutableMultiset.copyOf(c)} returns an {@code ImmutableMultiset<String>}
	* containing each of the strings in {@code c}, while
	* {@code ImmutableMultiset.of(c)} returns an
	* {@code ImmutableMultiset<Collection<String>>} containing one element (the
	* given collection itself).
	*
	* <p><b>Note:</b> Despite what the method name suggests, if {@code elements}
	* is an {@code ImmutableMultiset}, no copy will actually be performed, and
	* the given multiset itself will be returned.
	*
	* @throws NullPointerException if any of {@code elements} is null
	*/
	public static <E> ImmutableMultiset<E> copyOf(
	Iterable<? extends E> elements) {
	if (elements instanceof ImmutableMultiset) {
	@SuppressWarnings("unchecked") // all supported methods are covariant
	ImmutableMultiset<E> result = (ImmutableMultiset<E>) elements;
	return result;
	}

	@SuppressWarnings("unchecked") // the cast causes a warning
	Multiset<? extends E> multiset = (elements instanceof Multiset)
	? (Multiset<? extends E>) elements
	: LinkedHashMultiset.create(elements);

	return copyOfInternal(multiset);
	}

	private static <E> ImmutableMultiset<E> copyOfInternal(
	Multiset<? extends E> multiset) {
	long size = 0;
	ImmutableMap.Builder<E, Integer> builder = ImmutableMap.builder();

	for (Entry<? extends E> entry : multiset.entrySet()) {
	int count = entry.getCount();
	if (count > 0) {
	// Since ImmutableMap.Builder throws an NPE if an element is null, no
	// other null checks are needed.
	builder.put(entry.getElement(), count);
	size += count;
	}
	}

	if (size == 0) {
	return of();
	}
	return new ImmutableMultiset<E>(
	builder.build(), (int) Math.min(size, Integer.MAX_VALUE));
	}

	/**
	* Returns an immutable multiset containing the given elements.
	*
	* <p>The multiset is ordered by the first occurrence of each element. For
	* example,
	* {@code ImmutableMultiset.copyOf(Arrays.asList(2, 3, 1, 3).iterator())}
	* yields a multiset with elements in the order {@code 2, 3, 3, 1}.
	*
	* @throws NullPointerException if any of {@code elements} is null
	*/
	public static <E> ImmutableMultiset<E> copyOf(
	Iterator<? extends E> elements) {
	Multiset<E> multiset = LinkedHashMultiset.create();
	Iterators.addAll(multiset, elements);
	return copyOfInternal(multiset);
	}

	private final transient ImmutableMap<E, Integer> map;
	private 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.
	@SuppressWarnings("unchecked")
	// eclipse doesn't like the raw types here, but they're harmless
	private static class FieldSettersHolder {
	static final FieldSetter<ImmutableMultiset> MAP_FIELD_SETTER
	= Serialization.getFieldSetter(ImmutableMultiset.class, "map");
	static final FieldSetter<ImmutableMultiset> SIZE_FIELD_SETTER
	= Serialization.getFieldSetter(ImmutableMultiset.class, "size");
	}

	ImmutableMultiset(ImmutableMap<E, Integer> map, int size) {
	this.map = map;
	this.size = size;
	}

	public int count(@Nullable Object element) {
	Integer value = map.get(element);
	return (value == null) ? 0 : value;
	}

	@Override public UnmodifiableIterator<E> iterator() {
	final Iterator<Map.Entry<E, Integer>> mapIterator
	= map.entrySet().iterator();

	return new UnmodifiableIterator<E>() {
	int remaining;
	E element;

	public boolean hasNext() {
	return (remaining > 0) \|\| mapIterator.hasNext();
	}

	public E next() {
	if (remaining <= 0) {
	Map.Entry<E, Integer> entry = mapIterator.next();
	element = entry.getKey();
	remaining = entry.getValue();
	}
	remaining--;
	return element;
	}
	};
	}

	public int size() {
	return size;
	}

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

	/**
	* Guaranteed to throw an exception and leave the collection unmodified.
	*
	* @throws UnsupportedOperationException always
	*/
	public int add(E element, int occurrences) {
	throw new UnsupportedOperationException();
	}

	/**
	* Guaranteed to throw an exception and leave the collection unmodified.
	*
	* @throws UnsupportedOperationException always
	*/
	public int remove(Object element, int occurrences) {
	throw new UnsupportedOperationException();
	}

	/**
	* Guaranteed to throw an exception and leave the collection unmodified.
	*
	* @throws UnsupportedOperationException always
	*/
	public int setCount(E element, int count) {
	throw new UnsupportedOperationException();
	}

	/**
	* Guaranteed to throw an exception and leave the collection unmodified.
	*
	* @throws UnsupportedOperationException always
	*/
	public boolean setCount(E element, int oldCount, int newCount) {
	throw new UnsupportedOperationException();
	}

	@Override public boolean equals(@Nullable Object object) {
	if (object == this) {
	return true;
	}
	if (object instanceof Multiset) {
	Multiset<?> that = (Multiset<?>) object;
	if (this.size() != that.size()) {
	return false;
	}
	for (Entry<?> entry : that.entrySet()) {
	if (count(entry.getElement()) != entry.getCount()) {
	return false;
	}
	}
	return true;
	}
	return false;
	}

	@Override public int hashCode() {
	// could cache this, but not considered worthwhile to do so
	return map.hashCode();
	}

	@Override public String toString() {
	return entrySet().toString();
	}

	// TODO: Serialization of the element set should serialize the multiset, and
	// deserialization should call multiset.elementSet(). Then
	// reserialized(multiset).elementSet() == reserialized(multiset.elementSet())
	// Currently, those object references differ.
	public Set<E> elementSet() {
	return map.keySet();
	}

	private transient ImmutableSet<Entry<E>> entrySet;

	public Set<Entry<E>> entrySet() {
	ImmutableSet<Entry<E>> es = entrySet;
	return (es == null) ? (entrySet = new EntrySet<E>(this)) : es;
	}

	private static class EntrySet<E> extends ImmutableSet<Entry<E>> {
	final ImmutableMultiset<E> multiset;

	public EntrySet(ImmutableMultiset<E> multiset) {
	this.multiset = multiset;
	}

	@Override public UnmodifiableIterator<Entry<E>> iterator() {
	final Iterator<Map.Entry<E, Integer>> mapIterator
	= multiset.map.entrySet().iterator();
	return new UnmodifiableIterator<Entry<E>>() {
	public boolean hasNext() {
	return mapIterator.hasNext();
	}
	public Entry<E> next() {
	Map.Entry<E, Integer> mapEntry = mapIterator.next();
	return
	Multisets.immutableEntry(mapEntry.getKey(), mapEntry.getValue());
	}
	};
	}

	public int size() {
	return multiset.map.size();
	}

	@Override public boolean contains(Object o) {
	if (o instanceof Entry) {
	Entry<?> entry = (Entry<?>) o;
	if (entry.getCount() <= 0) {
	return false;
	}
	int count = multiset.count(entry.getElement());
	return count == entry.getCount();
	}
	return false;
	}

	@Override public int hashCode() {
	return multiset.map.hashCode();
	}

	@Override Object writeReplace() {
	return this;
	}

	private static final long serialVersionUID = 0;
	}

	/**
	* @serialData the number of distinct elements, the first element, its count,
	* the second element, its count, and so on
	*/
	private void writeObject(ObjectOutputStream stream) throws IOException {
	stream.defaultWriteObject();
	Serialization.writeMultiset(this, stream);
	}

	private void readObject(ObjectInputStream stream)
	throws IOException, ClassNotFoundException {
	stream.defaultReadObject();
	int entryCount = stream.readInt();
	ImmutableMap.Builder<E, Integer> builder = ImmutableMap.builder();
	long tmpSize = 0;
	for (int i = 0; i < entryCount; i++) {
	@SuppressWarnings("unchecked") // reading data stored by writeMultiset
	E element = (E) stream.readObject();
	int count = stream.readInt();
	if (count <= 0) {
	throw new InvalidObjectException("Invalid count " + count);
	}
	builder.put(element, count);
	tmpSize += count;
	}

	FieldSettersHolder.MAP_FIELD_SETTER.set(this, builder.build());
	FieldSettersHolder.SIZE_FIELD_SETTER.set(
	this, (int) Math.min(tmpSize, Integer.MAX_VALUE));
	}

	@Override Object writeReplace() {
	return this;
	}

	private static final long serialVersionUID = 0;

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

	/**
	* A builder for creating immutable multiset instances, especially
	* {@code public static final} multisets ("constant multisets").
	*
	* <p>Example:
	* <pre> {@code
	* public static final ImmutableMultiset<Bean> BEANS
	* = new ImmutableMultiset.Builder<Bean>()
	* .addCopies(Bean.COCOA, 4)
	* .addCopies(Bean.GARDEN, 6)
	* .addCopies(Bean.RED, 8)
	* .addCopies(Bean.BLACK_EYED, 10)
	* .build();}</pre>
	*
	* <p>Builder instances can be reused - it is safe to call {@link #build}
	* multiple times to build multiple multisets in series. Each multiset
	* is a superset of the multiset created before it.
	*/
	public static final class Builder<E> extends ImmutableCollection.Builder<E> {
	private final Multiset<E> contents = LinkedHashMultiset.create();

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

	/**
	* Adds {@code element} to the {@code ImmutableMultiset}.
	*
	* @param element the element to add
	* @return this {@code Builder} object
	* @throws NullPointerException if {@code element} is null
	*/
	@Override public Builder<E> add(E element) {
	contents.add(checkNotNull(element));
	return this;
	}

	/**
	* Adds a number of occurrences of an element to this {@code
	* ImmutableMultiset}.
	*
	* @param element the element to add
	* @param occurrences the number of occurrences of the element to add. May
	* be zero, in which case no change will be made.
	* @return this {@code Builder} object
	* @throws NullPointerException if {@code element} is null
	* @throws IllegalArgumentException if {@code occurrences} is negative, or
	* if this operation would result in more than {@link Integer#MAX_VALUE}
	* occurrences of the element
	*/
	public Builder<E> addCopies(E element, int occurrences) {
	contents.add(checkNotNull(element), occurrences);
	return this;
	}

	/**
	* Adds or removes the necessary occurrences of an element such that the
	* element attains the desired count.
	*
	* @param element the element to add or remove occurrences of
	* @param count the desired count of the element in this multiset
	* @return this {@code Builder} object
	* @throws NullPointerException if {@code element} is null
	* @throws IllegalArgumentException if {@code count} is negative
	*/
	public Builder<E> setCount(E element, int count) {
	contents.setCount(checkNotNull(element), count);
	return this;
	}

	/**
	* Adds each element of {@code elements} to the {@code ImmutableMultiset}.
	*
	* @param elements the elements to add
	* @return this {@code Builder} object
	* @throws NullPointerException if {@code elements} is null or contains a
	* null element
	*/
	@Override public Builder<E> add(E... elements) {
	super.add(elements);
	return this;
	}

	/**
	* Adds each element of {@code elements} to the {@code ImmutableMultiset}.
	*
	* @param elements the {@code Iterable} to add to the {@code
	* ImmutableMultiset}
	* @return this {@code Builder} object
	* @throws NullPointerException if {@code elements} is null or contains a
	* null element
	*/
	@Override public Builder<E> addAll(Iterable<? extends E> elements) {
	if (elements instanceof Multiset) {
	@SuppressWarnings("unchecked")
	Multiset<? extends E> multiset = (Multiset<? extends E>) elements;
	for (Entry<? extends E> entry : multiset.entrySet()) {
	addCopies(entry.getElement(), entry.getCount());
	}
	} else {
	super.addAll(elements);
	}
	return this;
	}

	/**
	* Adds each element of {@code elements} to the {@code ImmutableMultiset}.
	*
	* @param elements the elements to add to the {@code ImmutableMultiset}
	* @return this {@code Builder} object
	* @throws NullPointerException if {@code elements} is null or contains a
	* null element
	*/
	@Override public Builder<E> addAll(Iterator<? extends E> elements) {
	super.addAll(elements);
	return this;
	}

	/**
	* Returns a newly-created {@code ImmutableMultiset} based on the contents
	* of the {@code Builder}.
	*/
	@Override public ImmutableMultiset<E> build() {
	return copyOf(contents);
	}
	}
	}