android/guava/src/com/google/common/collect/Maps.java
static <K, V1, V2> EntryTransformer<K, V1, V2> asEntryTransformer(
      final Function<? super V1, V2> function) {
    checkNotNull(function);
    return new EntryTransformer<K, V1, V2>() {
      @Override
      public V2 transformEntry(K key, V1 value) {
        return function.apply(value);
      }
    };
  }
static <K, V1, V2> EntryTransformer<K, V1, V2> asEntryTransformer(
      final Function<? super V1, V2> function) {
    checkNotNull(function);
    return new EntryTransformer<K, V1, V2>() {
      @Override
      public V2 transformEntry(K key, V1 value) {
        return function.apply(value);
      }
    };
  }
Views a function as an entry transformer that ignores the entry key.