assertFalse(
        "A List should not equal another List containing different elements.",
        getList().equals(other));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_otherListContainingNull() {
    List<E> other = new ArrayList<>(getSampleElements());
    other.set(other.size() / 2, null);
    assertFalse(
        "Two Lists should not be equal if exactly one of them has null at a given index.",

    assertTrue(Objects.equal(1, 1));
    assertTrue(Objects.equal(null, null));

    // test distinct string objects
    String s1 = "foobar";
    String s2 = new String(s1);
    assertTrue(Objects.equal(s1, s2));

    assertFalse(Objects.equal(s1, null));
    assertFalse(Objects.equal(null, s1));
    assertFalse(Objects.equal("foo", "bar"));
    assertFalse(Objects.equal("1", 1));
  }

 *   <li>comparing each pair of objects within the same equality group returns true
 *   <li>comparing each pair of objects from different equality groups returns false
 *   <li>the hash codes of any two equal objects are equal
 * </ul>
 *
 * <p>When a test fails, the error message labels the objects involved in the failed comparison as
 * follows:
 *
 * <ul>

    /**
     * Do not instantiate.
     */
    protected ObjectUtil() {
    }

    /**
     * Returns true if the two objects are equal, or both are null.
     *
     * @param object1 the first object
     * @param object2 the second object
     * @return true if equal or both null, false otherwise
     */
    public static boolean equals(final Object object1, final Object object2) {
        if (object1 == object2) {

    assertFalse(
        "A List should not equal another List containing different elements.",
        getList().equals(other));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_otherListContainingNull() {
    List<E> other = new ArrayList<>(getSampleElements());
    other.set(other.size() / 2, null);
    assertFalse(
        "Two Lists should not be equal if exactly one of them has null at a given index.",

            this.calledName = null;
        }

        return this.calledName;
    }

    /*
     * There are three degrees of state that any NbtAddress can have.
     *
     * 1) IP Address - If a dot-quad IP string is used with getByName (or used
     * to create an NbtAddress internal to this netbios package), no query is
     * sent on the wire and the only state this object has is it's IP address

    /** Returns the value from the right map (possibly null). */
    @ParametricNullness
    V rightValue();

    /**
     * Two instances are considered equal if their {@link #leftValue()} values are equal and their
     * {@link #rightValue()} values are also equal.
     */
    @Override
    boolean equals(@Nullable Object other);

    /**

    assertTrue("An Object should be equal to itself.", collection.equals(collection));
  }

  // Comparisons to null *are* defined.
  @SuppressWarnings("UndefinedEquals")
  public void testEquals_null() {
    // noinspection ObjectEqualsNull
    assertFalse("An object should not be equal to null.", collection.equals(null));
  }

  // A collection should essentially never be equal to a non-collection.

          e, obj + " must not be Object#equals to an arbitrary object of another class");
      return;
    }
    fail("Should get equal to incompatible class error");
  }

  /** Test proper handling where an object is not equal to one the user has said should be equal */
  public void testInvalidNotEqualsEqualObject() {
    equalsTester.addEqualityGroup(reference, notEqualObject1);
    try {

   * A specification for which index to return if the list contains at least one element that
   * compares as equal to the key.
   */
  enum KeyPresentBehavior {
    /**
     * Return the index of any list element that compares as equal to the key. No guarantees are
     * made as to which index is returned, if more than one element compares as equal to the key.
     */
    ANY_PRESENT {
      @Override