test/java/util/Collections/EmptyNavigableMap.java - toolchain/jdk/jdk9_jdk - Git at Google

 /*
  * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 /*
  * @test
  * @bug 4533691 7129185
  * @summary Unit test for Collections.emptyNavigableMap
  * @run testng EmptyNavigableMap
  */
 import java.math.BigInteger;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.NavigableMap;
 import java.util.SortedMap;
 import java.util.TreeMap;

 import org.testng.Assert;
 import org.testng.Assert.ThrowingRunnable;
 import org.testng.annotations.Test;
 import org.testng.annotations.DataProvider;

 import static org.testng.Assert.assertTrue;
 import static org.testng.Assert.assertFalse;

 public class EmptyNavigableMap {

     public static <T> void assertInstance(T actual, Class<? extends T> expected) {
         assertInstance(expected.isInstance(actual), null);
     }

     public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {
         assertTrue(expected.isInstance(actual), ((null != message) ? message : "")
             + " " + (actual == null ? "<null>" : actual.getClass().getSimpleName()) + " != " + expected.getSimpleName() + ". ");
     }

     public static <T extends Throwable> void assertEmptyNavigableMap(Object obj) {
         assertInstance(obj, NavigableMap.class);
         assertTrue(((NavigableMap)obj).isEmpty() && (((NavigableMap)obj).size() == 0));
     }

     public static <T extends Throwable> void assertEmptyNavigableMap(Object obj, String message) {
         assertInstance(obj, NavigableMap.class, message);
         assertTrue(((NavigableMap)obj).isEmpty() && (((NavigableMap)obj).size() == 0),
             ((null != message) ? message : "") + " Not empty. ");
     }

     private <T extends Throwable> void assertThrows(Class<T> throwableClass,
                                                     ThrowingRunnable runnable,
                                                     String message) {
         try {
             Assert.assertThrows(throwableClass, runnable);
         } catch (AssertionError e) {
             throw new AssertionError(String.format("%s%n%s",
                     ((null != message) ? message : ""), e.getMessage()), e);
         }
     }

     private void assertThrowsCCE(ThrowingRunnable r, String s) {
         assertThrows(ClassCastException.class, r, s);
     }

     private void assertThrowsNPE(ThrowingRunnable r, String s) {
         assertThrows(NullPointerException.class, r, s);
     }

     private void assertThrowsIAE(ThrowingRunnable r, String s) {
         assertThrows(IllegalArgumentException.class, r, s);
     }

     public static final boolean isDescending(SortedMap<?,?> set) {
         if (null == set.comparator()) {
             // natural order
             return false;
         }

         if (Collections.reverseOrder() == set.comparator()) {
             // reverse natural order.
             return true;
         }

         if (set.comparator().equals(Collections.reverseOrder(Collections.reverseOrder(set.comparator())))) {
             // it's a Collections.reverseOrder(Comparator).
             return true;
         }

         throw new IllegalStateException("can't determine ordering for " + set);
     }

     /**
      * Tests that the comparator is {@code null}.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testComparatorIsNull(String description, NavigableMap<?,?> navigableMap) {
         Comparator comparator = navigableMap.comparator();

         assertTrue(comparator == null || comparator == Collections.reverseOrder(), description + ": Comparator (" + comparator + ") is not null.");
     }

     /**
      * Tests that contains requires Comparable
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testContainsRequiresComparable(String description, NavigableMap<?,?> navigableMap) {
         assertThrowsCCE(() -> {
             navigableMap.containsKey(new Object());
         },
             description + ": Compareable should be required");
     }

     /**
      * Tests that the contains method returns {@code false}.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testContains(String description, NavigableMap<?,?> navigableMap) {
         assertFalse(navigableMap.containsKey(new Integer(1)),
             description + ": Should not contain any elements.");
         assertFalse(navigableMap.containsValue(new Integer(1)),
             description + ": Should not contain any elements.");
     }

     /**
      * Tests that the containsAll method returns {@code false}.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testContainsAll(String description, NavigableMap<?,?> navigableMap) {
         TreeMap treeMap = new TreeMap();
         treeMap.put("1", 1);
         treeMap.put("2", 2);
         treeMap.put("3", 3);

         assertFalse(navigableMap.equals(treeMap), "Should not contain any elements.");
     }

     /**
      * Tests that the iterator is empty.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testEmptyIterator(String description, NavigableMap<?,?> navigableMap) {
         assertFalse(navigableMap.keySet().iterator().hasNext(), "The iterator is not empty.");
         assertFalse(navigableMap.values().iterator().hasNext(), "The iterator is not empty.");
         assertFalse(navigableMap.entrySet().iterator().hasNext(), "The iterator is not empty.");
     }

     /**
      * Tests that the set is empty.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testIsEmpty(String description, NavigableMap<?,?> navigableMap) {
         assertTrue(navigableMap.isEmpty(), "The set is not empty.");
     }

     /**
      * Tests the headMap() method.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testHeadMap(String description, NavigableMap navigableMap) {
         assertThrowsNPE(
             () -> { NavigableMap ss = navigableMap.headMap(null, false); },
             description + ": Must throw NullPointerException for null element");

         assertThrowsCCE(
             () -> { NavigableMap ss = navigableMap.headMap(new Object(), true); },
             description + ": Must throw ClassCastException for non-Comparable element");

         NavigableMap ss = navigableMap.headMap("1", false);

         assertEmptyNavigableMap(ss, description + ": Returned value is not empty navigable set.");
     }

     /**
      * Tests that the size is 0.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testSizeIsZero(String description, NavigableMap<?,?> navigableMap) {
         assertTrue(0 == navigableMap.size(), "The size of the set is not 0.");
     }

     /**
      * Tests the subMap() method.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testSubMap(String description, NavigableMap navigableMap) {
         assertThrowsNPE(
             () -> {
                 SortedMap ss = navigableMap.subMap(null, BigInteger.TEN);
             },
             description + ": Must throw NullPointerException for null element");

         assertThrowsNPE(
             () -> {
                 SortedMap ss = navigableMap.subMap(BigInteger.ZERO, null);
             },
             description + ": Must throw NullPointerException for null element");

         assertThrowsNPE(
             () -> {
                 SortedMap ss = navigableMap.subMap(null, null);
             },
             description + ": Must throw NullPointerException for null element");

         Object obj1 = new Object();
         Object obj2 = new Object();

         assertThrowsCCE(
             () -> {
                 SortedMap ss = navigableMap.subMap(obj1, BigInteger.TEN);
             },
             description + ": Must throw ClassCastException for parameter which is not Comparable.");

         assertThrowsCCE(
             () -> {
                 SortedMap ss = navigableMap.subMap(BigInteger.ZERO, obj2);
             },
             description + ": Must throw ClassCastException for parameter which is not Comparable.");

         assertThrowsCCE(
             () -> {
                 SortedMap ss = navigableMap.subMap(obj1, obj2);
             },
             description + ": Must throw ClassCastException for parameter which is not Comparable.");

         // minimal range
         navigableMap.subMap(BigInteger.ZERO, false, BigInteger.ZERO, false);
         navigableMap.subMap(BigInteger.ZERO, false, BigInteger.ZERO, true);
         navigableMap.subMap(BigInteger.ZERO, true, BigInteger.ZERO, false);
         navigableMap.subMap(BigInteger.ZERO, true, BigInteger.ZERO, true);

         Object first = isDescending(navigableMap) ? BigInteger.TEN : BigInteger.ZERO;
         Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;

             assertThrowsIAE(
                 () -> {
                     navigableMap.subMap(last, true, first, false);
                 },
                 description + ": Must throw IllegalArgumentException when fromElement is not less than toElement.");

         navigableMap.subMap(first, true, last, false);
     }

     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testSubMapRanges(String description, NavigableMap navigableMap) {
         Object first = isDescending(navigableMap) ? BigInteger.TEN : BigInteger.ZERO;
         Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;

         NavigableMap subMap = navigableMap.subMap(first, true, last, true);

         // same subset
         subMap.subMap(first, true, last, true);

         // slightly smaller
         NavigableMap ns = subMap.subMap(first, false, last, false);
         // slight expansion
         assertThrowsIAE(() -> {
             ns.subMap(first, true, last, true);
         },
             description + ": Expansion should not be allowed");

         // much smaller
         subMap.subMap(first, false, BigInteger.ONE, false);
     }

     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testheadMapRanges(String description, NavigableMap navigableMap) {
         NavigableMap subMap = navigableMap.headMap(BigInteger.ONE, true);

         // same subset
         subMap.headMap(BigInteger.ONE, true);

         // slightly smaller
         NavigableMap ns = subMap.headMap(BigInteger.ONE, false);

         // slight expansion
         assertThrowsIAE(() -> {
             ns.headMap(BigInteger.ONE, true);
         },
             description + ": Expansion should not be allowed");

         // much smaller
         subMap.headMap(isDescending(subMap) ? BigInteger.TEN : BigInteger.ZERO, true);
     }

     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testTailMapRanges(String description, NavigableMap navigableMap) {
         NavigableMap subMap = navigableMap.tailMap(BigInteger.ONE, true);

         // same subset
         subMap.tailMap(BigInteger.ONE, true);

         // slightly smaller
         NavigableMap ns = subMap.tailMap(BigInteger.ONE, false);

         // slight expansion
         assertThrowsIAE(() -> {
             ns.tailMap(BigInteger.ONE, true);
         },
             description + ": Expansion should not be allowed");

         // much smaller
         subMap.tailMap(isDescending(subMap) ? BigInteger.ZERO : BigInteger.TEN, false);
     }

     /**
      * Tests the tailMap() method.
      */
     @Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
     public void testTailMap(String description, NavigableMap navigableMap) {
         assertThrowsNPE(() -> {
             navigableMap.tailMap(null);
         },
             description + ": Must throw NullPointerException for null element");

         assertThrowsCCE(() -> {
             navigableMap.tailMap(new Object());
         },
             description);

         NavigableMap ss = navigableMap.tailMap("1", true);

         assertEmptyNavigableMap(ss, description + ": Returned value is not empty navigable set.");
     }

     @DataProvider(name = "NavigableMap<?,?>", parallel = true)
     public static Iterator<Object[]> navigableMapsProvider() {
         return makeNavigableMaps().iterator();
     }

     public static Collection<Object[]> makeNavigableMaps() {
         return Arrays.asList(
             new Object[]{"UnmodifiableNavigableMap(TreeMap)", Collections.unmodifiableNavigableMap(new TreeMap())},
             new Object[]{"UnmodifiableNavigableMap(TreeMap.descendingMap()", Collections.unmodifiableNavigableMap(new TreeMap().descendingMap())},
             new Object[]{"UnmodifiableNavigableMap(TreeMap.descendingMap().descendingMap()", Collections.unmodifiableNavigableMap(new TreeMap().descendingMap().descendingMap())},
             new Object[]{"emptyNavigableMap()", Collections.emptyNavigableMap()},
             new Object[]{"emptyNavigableMap().descendingMap()", Collections.emptyNavigableMap().descendingMap()},
             new Object[]{"emptyNavigableMap().descendingMap().descendingMap()", Collections.emptyNavigableMap().descendingMap().descendingMap()}
         );
     }
 }
	/*
	* Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/*
	* @test
	* @bug 4533691 7129185
	* @summary Unit test for Collections.emptyNavigableMap
	* @run testng EmptyNavigableMap
	*/
	import java.math.BigInteger;
	import java.util.Arrays;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.Iterator;
	import java.util.NavigableMap;
	import java.util.SortedMap;
	import java.util.TreeMap;

	import org.testng.Assert;
	import org.testng.Assert.ThrowingRunnable;
	import org.testng.annotations.Test;
	import org.testng.annotations.DataProvider;

	import static org.testng.Assert.assertTrue;
	import static org.testng.Assert.assertFalse;

	public class EmptyNavigableMap {

	public static <T> void assertInstance(T actual, Class<? extends T> expected) {
	assertInstance(expected.isInstance(actual), null);
	}

	public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {
	assertTrue(expected.isInstance(actual), ((null != message) ? message : "")
	+ " " + (actual == null ? "<null>" : actual.getClass().getSimpleName()) + " != " + expected.getSimpleName() + ". ");
	}

	public static <T extends Throwable> void assertEmptyNavigableMap(Object obj) {
	assertInstance(obj, NavigableMap.class);
	assertTrue(((NavigableMap)obj).isEmpty() && (((NavigableMap)obj).size() == 0));
	}

	public static <T extends Throwable> void assertEmptyNavigableMap(Object obj, String message) {
	assertInstance(obj, NavigableMap.class, message);
	assertTrue(((NavigableMap)obj).isEmpty() && (((NavigableMap)obj).size() == 0),
	((null != message) ? message : "") + " Not empty. ");
	}

	private <T extends Throwable> void assertThrows(Class<T> throwableClass,
	ThrowingRunnable runnable,
	String message) {
	try {
	Assert.assertThrows(throwableClass, runnable);
	} catch (AssertionError e) {
	throw new AssertionError(String.format("%s%n%s",
	((null != message) ? message : ""), e.getMessage()), e);
	}
	}

	private void assertThrowsCCE(ThrowingRunnable r, String s) {
	assertThrows(ClassCastException.class, r, s);
	}

	private void assertThrowsNPE(ThrowingRunnable r, String s) {
	assertThrows(NullPointerException.class, r, s);
	}

	private void assertThrowsIAE(ThrowingRunnable r, String s) {
	assertThrows(IllegalArgumentException.class, r, s);
	}

	public static final boolean isDescending(SortedMap<?,?> set) {
	if (null == set.comparator()) {
	// natural order
	return false;
	}

	if (Collections.reverseOrder() == set.comparator()) {
	// reverse natural order.
	return true;
	}

	if (set.comparator().equals(Collections.reverseOrder(Collections.reverseOrder(set.comparator())))) {
	// it's a Collections.reverseOrder(Comparator).
	return true;
	}

	throw new IllegalStateException("can't determine ordering for " + set);
	}

	/**
	* Tests that the comparator is {@code null}.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testComparatorIsNull(String description, NavigableMap<?,?> navigableMap) {
	Comparator comparator = navigableMap.comparator();

	assertTrue(comparator == null \|\| comparator == Collections.reverseOrder(), description + ": Comparator (" + comparator + ") is not null.");
	}

	/**
	* Tests that contains requires Comparable
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testContainsRequiresComparable(String description, NavigableMap<?,?> navigableMap) {
	assertThrowsCCE(() -> {
	navigableMap.containsKey(new Object());
	},
	description + ": Compareable should be required");
	}

	/**
	* Tests that the contains method returns {@code false}.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testContains(String description, NavigableMap<?,?> navigableMap) {
	assertFalse(navigableMap.containsKey(new Integer(1)),
	description + ": Should not contain any elements.");
	assertFalse(navigableMap.containsValue(new Integer(1)),
	description + ": Should not contain any elements.");
	}

	/**
	* Tests that the containsAll method returns {@code false}.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testContainsAll(String description, NavigableMap<?,?> navigableMap) {
	TreeMap treeMap = new TreeMap();
	treeMap.put("1", 1);
	treeMap.put("2", 2);
	treeMap.put("3", 3);

	assertFalse(navigableMap.equals(treeMap), "Should not contain any elements.");
	}

	/**
	* Tests that the iterator is empty.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testEmptyIterator(String description, NavigableMap<?,?> navigableMap) {
	assertFalse(navigableMap.keySet().iterator().hasNext(), "The iterator is not empty.");
	assertFalse(navigableMap.values().iterator().hasNext(), "The iterator is not empty.");
	assertFalse(navigableMap.entrySet().iterator().hasNext(), "The iterator is not empty.");
	}

	/**
	* Tests that the set is empty.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testIsEmpty(String description, NavigableMap<?,?> navigableMap) {
	assertTrue(navigableMap.isEmpty(), "The set is not empty.");
	}

	/**
	* Tests the headMap() method.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testHeadMap(String description, NavigableMap navigableMap) {
	assertThrowsNPE(
	() -> { NavigableMap ss = navigableMap.headMap(null, false); },
	description + ": Must throw NullPointerException for null element");

	assertThrowsCCE(
	() -> { NavigableMap ss = navigableMap.headMap(new Object(), true); },
	description + ": Must throw ClassCastException for non-Comparable element");

	NavigableMap ss = navigableMap.headMap("1", false);

	assertEmptyNavigableMap(ss, description + ": Returned value is not empty navigable set.");
	}

	/**
	* Tests that the size is 0.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testSizeIsZero(String description, NavigableMap<?,?> navigableMap) {
	assertTrue(0 == navigableMap.size(), "The size of the set is not 0.");
	}

	/**
	* Tests the subMap() method.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testSubMap(String description, NavigableMap navigableMap) {
	assertThrowsNPE(
	() -> {
	SortedMap ss = navigableMap.subMap(null, BigInteger.TEN);
	},
	description + ": Must throw NullPointerException for null element");

	assertThrowsNPE(
	() -> {
	SortedMap ss = navigableMap.subMap(BigInteger.ZERO, null);
	},
	description + ": Must throw NullPointerException for null element");

	assertThrowsNPE(
	() -> {
	SortedMap ss = navigableMap.subMap(null, null);
	},
	description + ": Must throw NullPointerException for null element");

	Object obj1 = new Object();
	Object obj2 = new Object();

	assertThrowsCCE(
	() -> {
	SortedMap ss = navigableMap.subMap(obj1, BigInteger.TEN);
	},
	description + ": Must throw ClassCastException for parameter which is not Comparable.");

	assertThrowsCCE(
	() -> {
	SortedMap ss = navigableMap.subMap(BigInteger.ZERO, obj2);
	},
	description + ": Must throw ClassCastException for parameter which is not Comparable.");

	assertThrowsCCE(
	() -> {
	SortedMap ss = navigableMap.subMap(obj1, obj2);
	},
	description + ": Must throw ClassCastException for parameter which is not Comparable.");

	// minimal range
	navigableMap.subMap(BigInteger.ZERO, false, BigInteger.ZERO, false);
	navigableMap.subMap(BigInteger.ZERO, false, BigInteger.ZERO, true);
	navigableMap.subMap(BigInteger.ZERO, true, BigInteger.ZERO, false);
	navigableMap.subMap(BigInteger.ZERO, true, BigInteger.ZERO, true);

	Object first = isDescending(navigableMap) ? BigInteger.TEN : BigInteger.ZERO;
	Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;

	assertThrowsIAE(
	() -> {
	navigableMap.subMap(last, true, first, false);
	},
	description + ": Must throw IllegalArgumentException when fromElement is not less than toElement.");

	navigableMap.subMap(first, true, last, false);
	}

	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testSubMapRanges(String description, NavigableMap navigableMap) {
	Object first = isDescending(navigableMap) ? BigInteger.TEN : BigInteger.ZERO;
	Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;

	NavigableMap subMap = navigableMap.subMap(first, true, last, true);

	// same subset
	subMap.subMap(first, true, last, true);

	// slightly smaller
	NavigableMap ns = subMap.subMap(first, false, last, false);
	// slight expansion
	assertThrowsIAE(() -> {
	ns.subMap(first, true, last, true);
	},
	description + ": Expansion should not be allowed");

	// much smaller
	subMap.subMap(first, false, BigInteger.ONE, false);
	}

	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testheadMapRanges(String description, NavigableMap navigableMap) {
	NavigableMap subMap = navigableMap.headMap(BigInteger.ONE, true);

	// same subset
	subMap.headMap(BigInteger.ONE, true);

	// slightly smaller
	NavigableMap ns = subMap.headMap(BigInteger.ONE, false);

	// slight expansion
	assertThrowsIAE(() -> {
	ns.headMap(BigInteger.ONE, true);
	},
	description + ": Expansion should not be allowed");

	// much smaller
	subMap.headMap(isDescending(subMap) ? BigInteger.TEN : BigInteger.ZERO, true);
	}

	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testTailMapRanges(String description, NavigableMap navigableMap) {
	NavigableMap subMap = navigableMap.tailMap(BigInteger.ONE, true);

	// same subset
	subMap.tailMap(BigInteger.ONE, true);

	// slightly smaller
	NavigableMap ns = subMap.tailMap(BigInteger.ONE, false);

	// slight expansion
	assertThrowsIAE(() -> {
	ns.tailMap(BigInteger.ONE, true);
	},
	description + ": Expansion should not be allowed");

	// much smaller
	subMap.tailMap(isDescending(subMap) ? BigInteger.ZERO : BigInteger.TEN, false);
	}

	/**
	* Tests the tailMap() method.
	*/
	@Test(dataProvider = "NavigableMap<?,?>", dataProviderClass = EmptyNavigableMap.class)
	public void testTailMap(String description, NavigableMap navigableMap) {
	assertThrowsNPE(() -> {
	navigableMap.tailMap(null);
	},
	description + ": Must throw NullPointerException for null element");

	assertThrowsCCE(() -> {
	navigableMap.tailMap(new Object());
	},
	description);

	NavigableMap ss = navigableMap.tailMap("1", true);

	assertEmptyNavigableMap(ss, description + ": Returned value is not empty navigable set.");
	}

	@DataProvider(name = "NavigableMap<?,?>", parallel = true)
	public static Iterator<Object[]> navigableMapsProvider() {
	return makeNavigableMaps().iterator();
	}

	public static Collection<Object[]> makeNavigableMaps() {
	return Arrays.asList(
	new Object[]{"UnmodifiableNavigableMap(TreeMap)", Collections.unmodifiableNavigableMap(new TreeMap())},
	new Object[]{"UnmodifiableNavigableMap(TreeMap.descendingMap()", Collections.unmodifiableNavigableMap(new TreeMap().descendingMap())},
	new Object[]{"UnmodifiableNavigableMap(TreeMap.descendingMap().descendingMap()", Collections.unmodifiableNavigableMap(new TreeMap().descendingMap().descendingMap())},
	new Object[]{"emptyNavigableMap()", Collections.emptyNavigableMap()},
	new Object[]{"emptyNavigableMap().descendingMap()", Collections.emptyNavigableMap().descendingMap()},
	new Object[]{"emptyNavigableMap().descendingMap().descendingMap()", Collections.emptyNavigableMap().descendingMap().descendingMap()}
	);
	}
	}