new EqualsTester()
        .addEqualityGroup(
            Equivalence.identity().onResultOf(Functions.toStringFunction()),
            Equivalence.identity().onResultOf(Functions.toStringFunction()))
        .addEqualityGroup(Equivalence.equals().onResultOf(Functions.toStringFunction()))
        .addEqualityGroup(Equivalence.identity().onResultOf(Functions.identity()))
        .testEquals();
  }

  public void testEquivalentTo() {

    new EqualsTester()
        .addEqualityGroup(
            Equivalence.identity().onResultOf(Functions.toStringFunction()),
            Equivalence.identity().onResultOf(Functions.toStringFunction()))
        .addEqualityGroup(Equivalence.equals().onResultOf(Functions.toStringFunction()))
        .addEqualityGroup(Equivalence.identity().onResultOf(Functions.identity()))
        .testEquals();
  }

  public void testEquivalentTo() {

    Map<String, Integer> expected = Maps.transformValues(underlying, Functions.<Integer>identity());

    assertMapsEqual(expected, expected);

    Map<String, Integer> equalToUnderlying = Maps.newTreeMap();
    equalToUnderlying.putAll(underlying);
    Map<String, Integer> map =
        Maps.transformValues(equalToUnderlying, Functions.<Integer>identity());
    assertMapsEqual(expected, map);

    map =

    assertSame(stringIdentityConverter, stringIdentityConverter.reverse());
    assertSame(STR_TO_LONG, stringIdentityConverter.andThen(STR_TO_LONG));

    assertSame(STR_VAL, stringIdentityConverter.convert(STR_VAL));
    assertSame(STR_VAL, stringIdentityConverter.reverse().convert(STR_VAL));

    assertEquals("Converter.identity()", stringIdentityConverter.toString());

    assertSame(stringIdentityConverter, stringIdentityConverter.reverse());
    assertSame(STR_TO_LONG, stringIdentityConverter.andThen(STR_TO_LONG));

    assertSame(STR_VAL, stringIdentityConverter.convert(STR_VAL));
    assertSame(STR_VAL, stringIdentityConverter.reverse().convert(STR_VAL));

    assertEquals("Converter.identity()", stringIdentityConverter.toString());

    }

    @Override
    public int hashCode() {
      return identity;
    }

    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj instanceof FreshInvocationHandler) {
        FreshInvocationHandler that = (FreshInvocationHandler) obj;
        return identity == that.identity;
      }
      return false;
    }

    @Override
    public String toString() {

    }
  }

  /**
   * Returns the identity function.
   *
   * <p><b>Discouraged:</b> Prefer using a lambda like {@code v -> v}, which is shorter and often
   * more readable.
   */
  // implementation is "fully variant"; E has become a "pass-through" type
  @SuppressWarnings("unchecked")
  public static <E extends @Nullable Object> Function<E, E> identity() {
    return (Function<E, E>) IdentityFunction.INSTANCE;
  }

import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.codehaus.plexus.classworlds.realm.ClassRealm;

import static java.util.function.Function.identity;
import static java.util.stream.Collectors.collectingAndThen;
import static java.util.stream.Collectors.toMap;

/**

    }
  }

  public void testTransform_rejectionPropagatesToOutput() throws Exception {
    SettableFuture<Foo> input = SettableFuture.create();
    Function<Foo, Foo> identity = identity();
    ListenableFuture<Foo> transformed = transform(input, identity, REJECTING_EXECUTOR);
    input.set(new Foo());
    try {
      getDone(transformed);
      fail();
    } catch (ExecutionException expected) {

   * Arrays#hashCode(Object[])}. Note that array arguments to this method, with the exception of a
   * single Object array, do not get any special handling; their hash codes are based on identity
   * and not contents.
   *
   * <p>This is useful for implementing {@link Object#hashCode()}. For example, in an object that
   * has three properties, {@code x}, {@code y}, and {@code z}, one could write:
   *