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

  public void testTransformSingletonMapEquality() {
    Map<String, String> map =
        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()),

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

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

    SerializableTester.reserializeAndAssert(composedConverter);
  }

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

    Map<String, Integer> underlying = Maps.newHashMap();
    underlying.put("a", 1);
    underlying.put("b", 2);
    underlying.put("c", 3);
    return transformValues(underlying, Functions.toStringFunction());
  }

 * 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 static java.util.Arrays.asList;

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

    SortedMap<String, Integer> underlying = Maps.newTreeMap();
    underlying.put("a", 1);
    underlying.put("b", 2);
    underlying.put("c", 3);
    return transformValues(underlying, Functions.toStringFunction());
  }

    Map<String, Integer> underlying = Maps.newHashMap();
    underlying.put("a", 1);
    underlying.put("b", 2);
    underlying.put("c", 3);
    return transformValues(underlying, Functions.toStringFunction());
  }

    assertEquals(Optional.absent(), Optional.absent().transform(Functions.toStringFunction()));
  }

  public void testTransform_presentIdentity() {
    assertEquals(Optional.of("a"), Optional.of("a").transform(Functions.identity()));
  }

  public void testTransform_presentToString() {
    assertEquals(Optional.of("42"), Optional.of(42).transform(Functions.toStringFunction()));
  }

            .put("1", "1")
            .put("2", 2)
            .put("2", 2L)
            .build();

    ImmutableMultimap<String, Object> outputMap =
        Multimaps.index(stringToObject.values(), Functions.toStringFunction());
    assertEquals(stringToObject, outputMap);
  }

  public void testIndexIterator() {
    final Multimap<String, Object> stringToObject =
        new ImmutableMultimap.Builder<String, Object>()