assertTrue(item + " must not be Object#equals to null", !item.equals(null));
      assertTrue(
          item + " must not be Object#equals to an arbitrary object of another class",
          !item.equals(NotAnInstance.EQUAL_TO_NOTHING));
      assertTrue(item + " must be Object#equals to itself", item.equals(item));
      assertEquals(

        "Two Maps should not be equal if exactly one of them contains a null value.",
        getMap().equals(other));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_smallerMap() {
    Collection<Entry<K, V>> fewerEntries = getSampleEntries(getNumEntries() - 1);
    assertFalse(
        "Maps of different sizes should not be equal.", getMap().equals(newHashMap(fewerEntries)));
  }

        // We already know that nodeU equals other.nodeU. Combined with the earlier statement,
        // and the transitive property of equality, this implies that nodeU equals nodeV.
        // If nodeU equals nodeV, condition1 == condition2, so checking condition1 is sufficient.
        return nodeV().equals(other.nodeV());
      }

    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.

        checkRoundingUnnecessary(sqrtFloor.pow(2).equals(x)); // fall through
      case FLOOR:
      case DOWN:
        return sqrtFloor;
      case CEILING:
      case UP:
        int sqrtFloorInt = sqrtFloor.intValue();
        boolean sqrtFloorIsExact =
            (sqrtFloorInt * sqrtFloorInt == x.intValue()) // fast check mod 2^32
                && sqrtFloor.pow(2).equals(x); // slow exact check

    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.

      // filter out equals/hashCode/toString
      if (method.getName().equals("equals")
          && method.getParameterTypes().length == 1
          && method.getParameterTypes()[0] == Object.class) {
        continue;
      }
      if (method.getName().equals("hashCode") && method.getParameterTypes().length == 0) {
        continue;
      }

          e,
          equalObject1
              + " [group 1, item 1] must be Object#equals to "
              + notEqualObject1
              + " [group 1, item 2]");
      return;
    }
    fail("Should get not equal to equal object error");
  }

  /**
   * Test EqualsTester with no equals or not equals objects. This checks proper handling of null,
   * incompatible class and reflexive tests
   */

   * same structural relationships as those in this network.
   *
   * <p>Thus, two networks A and B are equal if <b>all</b> of the following are true:
   *
   * <ul>
   *   <li>A and B have equal {@link #isDirected() directedness}.
   *   <li>A and B have equal {@link #nodes() node sets}.
   *   <li>A and B have equal {@link #edges() edge sets}.
   *   <li>Every edge in A and B connects the same nodes in the same direction (if any).

    @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);

    /**
     * The hash code equals the value {@code Arrays.asList(leftValue(), rightValue()).hashCode()}.
     */
    @Override