/** 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(@CheckForNull Object other);

    /**

    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>

 *   <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>

	switch op {
	case opLt:
		return left.Before(right)
	case opLte:
		return left.Before(right) || left.Equal(right)
	case opGt:
		return left.After(right)
	case opGte:
		return left.After(right) || left.Equal(right)
	case opEq:
		return left.Equal(right)
	case opIneq:
		return !left.Equal(right)
	}
	// This case does not happen
	return false

  origin: GrandCastle
`

	g.Expect(output).To(Equal(expectedOutput))
}

func TestFormatter_PrintEmpty(t *testing.T) {
	g := NewWithT(t)

	msgs := diag.Messages{}

	logOutput, _ := Print(msgs, LogFormat, false)
	g.Expect(logOutput).To(Equal(""))

	jsonOutput, _ := Print(msgs, JSONFormat, false)
	g.Expect(jsonOutput).To(Equal("[]"))

	yamlOutput, _ := Print(msgs, YAMLFormat, false)

    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));
  }

    assertFalse(
        "Two Sets should not be equal if exactly one of them contains null.",
        getSet().equals(other));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_smallerSet() {
    Collection<E> fewerElements = getSampleElements(getNumElements() - 1);
    assertFalse(
        "Sets of different sizes should not be equal.",
        getSet().equals(MinimalSet.from(fewerElements)));

    assertFalse(
        "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)));
  }

    assertFalse(
        "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)));
  }