Map<String, String> map =
        Maps.transformValues(ImmutableMap.<String, Integer>of(), Functions.toStringFunction());
    assertMapsEqual(Maps.newHashMap(), map);
  }

  public void testTransformSingletonMapEquality() {
    Map<String, String> map =
        Maps.transformValues(ImmutableMap.of("a", 1), Functions.toStringFunction());
    Map<String, String> expected = ImmutableMap.of("a", "1");
    assertMapsEqual(expected, map);

    EquivalenceTester.of(Equivalence.equals().onResultOf(Functions.toStringFunction()))
        .addEquivalenceGroup(new IntValue(1), new IntValue(1))
        .addEquivalenceGroup(new IntValue(2))
        .test();
  }

  public void testOnResultOf_equals() {
    new EqualsTester()
        .addEqualityGroup(
            Equivalence.identity().onResultOf(Functions.toStringFunction()),

    SerializableTester.reserializeAndAssert(composedConverter);
  }

  public void testSerialization_from() {
    Converter<String, String> dumb = Converter.from(toStringFunction(), toStringFunction());
    SerializableTester.reserializeAndAssert(dumb);
  }

    Map<String, String> map =
        Maps.transformValues(ImmutableMap.<String, Integer>of(), Functions.toStringFunction());
    assertMapsEqual(Maps.newHashMap(), map);
  }

  public void testTransformSingletonMapEquality() {
    Map<String, String> map =
        Maps.transformValues(ImmutableMap.of("a", 1), Functions.toStringFunction());
    Map<String, String> expected = ImmutableMap.of("a", "1");
    assertMapsEqual(expected, map);

    Map<String, String> map =
        Maps.transformValues(ImmutableMap.<String, Integer>of(), Functions.toStringFunction());
    assertMapsEqual(Maps.newHashMap(), map);
  }

  public void testTransformSingletonMapEquality() {
    Map<String, String> map =
        Maps.transformValues(ImmutableMap.of("a", 1), Functions.toStringFunction());
    Map<String, String> expected = ImmutableMap.of("a", "1");
    assertMapsEqual(expected, map);

    checkCanReserializeSingleton(Functions.identity());
  }

  public void testToStringFunction_apply() {
    assertEquals("3", Functions.toStringFunction().apply(3));
    assertEquals("hiya", Functions.toStringFunction().apply("hiya"));
    assertEquals(
        "I'm a string",
        Functions.toStringFunction()
            .apply(
                new Object() {
                  @Override
                  public String toString() {

    checkCanReserializeSingleton(Functions.identity());
  }

  public void testToStringFunction_apply() {
    assertEquals("3", Functions.toStringFunction().apply(3));
    assertEquals("hiya", Functions.toStringFunction().apply("hiya"));
    assertEquals(
        "I'm a string",
        Functions.toStringFunction()
            .apply(
                new Object() {
                  @Override
                  public String toString() {

   * for more important information about the Java 8+ transition.
   */
  public static Function<Object, String> toStringFunction() {
    return ToStringFunction.INSTANCE;
  }

  // enum singleton pattern
  private enum ToStringFunction implements Function<Object, String> {
    INSTANCE;

    @Override
    public String apply(Object o) {
      checkNotNull(o); // eager for GWT.

    Map<String, String> map =
        Maps.transformValues(ImmutableMap.<String, Integer>of(), Functions.toStringFunction());
    assertMapsEqual(Maps.newHashMap(), map);
  }

  public void testTransformSingletonMapEquality() {
    Map<String, String> map =
        Maps.transformValues(ImmutableMap.of("a", 1), Functions.toStringFunction());
    Map<String, String> expected = ImmutableMap.of("a", "1");
    assertMapsEqual(expected, map);

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Functions.toStringFunction;
import static com.google.common.collect.Maps.uniqueIndex;

import com.google.caliper.BeforeExperiment;
import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import com.google.caliper.api.Footprint;