import org.jspecify.annotations.Nullable;

/**
 * Tester for equals() and hashCode() methods of a class.
 *
 * <p>The simplest use case is:
 *
 * <pre>
 * new EqualsTester().addEqualityGroup(foo).testEquals();
 * </pre>
 *
 * <p>This tests {@code foo.equals(foo)}, {@code foo.equals(null)}, and a few other operations.
 *
 * <p>For more extensive testing, add multiple equality groups. Each group should contain objects

  }

  public <A, B> void testEquals() throws Exception {
    Method method = TypeParameterTest.class.getDeclaredMethod("testEquals");
    new EqualsTester()
        .addEqualityGroup(new TypeParameter<A>() {}, new TypeParameter<A>() {})
        .addEqualityGroup(new TypeParameter<B>() {})
        .testEquals();
  }

  public void testNullPointers() {

              }
            });
  }

  public void testEquals() {
    ListMultimap<Integer, String> map1 = ImmutableListMultimap.of(1, "one");
    ListMultimap<Integer, String> map2 = ImmutableListMultimap.of(2, "two");
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

              }
            });
  }

  public void testEquals() {
    ListMultimap<Integer, String> map1 = ImmutableListMultimap.of(1, "one");
    ListMultimap<Integer, String> map2 = ImmutableListMultimap.of(2, "two");
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

              }
            });
  }

  public void testEquals() {
    SetMultimap<Integer, String> map1 = ImmutableSetMultimap.of(1, "one");
    SetMultimap<Integer, String> map2 = ImmutableSetMultimap.of(2, "two");
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

            });
  }

  public void testEquals() {
    SortedSetMultimap<Integer, String> map1 = TreeMultimap.create(ImmutableMultimap.of(1, "one"));
    SortedSetMultimap<Integer, String> map2 = TreeMultimap.create(ImmutableMultimap.of(2, "two"));
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

            getMultiset(), getSubjectGenerator().create(getSampleElements().toArray()))
        .testEquals();
  }

  @CollectionSize.Require(absent = ZERO)
  public void testNotEqualsEmpty() {
    new EqualsTester()
        .addEqualityGroup(getMultiset())
        .addEqualityGroup(getSubjectGenerator().create())
        .testEquals();
  }

  public void testHashCodeMatchesEntrySet() {

        .addEqualityGroup(immutableCell("foo", 1, 'b'))
        .addEqualityGroup(
            Tables.<@Nullable Object, @Nullable Object, @Nullable Object>immutableCell(
                null, null, null))
        .testEquals();
  }

  public void testEntryEqualsNull() {
    Cell<@Nullable String, @Nullable Integer, @Nullable Character> entry =
        immutableCell(null, null, null);

    new EqualsTester()

    List<String> proxy = newDelegatingList(LIST1);
    assertThat(proxy.toString()).isEqualTo(Proxy.getInvocationHandler(proxy).toString());
  }

  interface A {}

  interface B {}

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(newDelegatingList(LIST1))
        // Actually, this violates List#equals contract.
        // But whatever, no one is going to proxy List (hopefully).

  // create(Enum1.class) is equal to create(Enum2.class) but testEquals() expects otherwise.
  // For the same reason, we need to skip create(Iterable, Class).
  private static class EnumMultisetFactory {
    @Keep // used reflectively by testEquals
    public static <E extends Enum<E>> EnumMultiset<E> create(Iterable<E> elements) {
      return EnumMultiset.create(elements);