this.transformer = checkNotNull(transformer);
    }

    Collection<V2> transform(@ParametricNullness K key, Collection<V1> values) {
      Function<? super V1, V2> function = Maps.asValueToValueFunction(transformer, key);
      if (values instanceof List) {
        return Lists.transform((List<V1>) values, function);
      } else {
        return Collections2.transform(values, function);
      }
    }

      this.transformer = checkNotNull(transformer);
    }

    Collection<V2> transform(@ParametricNullness K key, Collection<V1> values) {
      Function<? super V1, V2> function = Maps.asValueToValueFunction(transformer, key);
      if (values instanceof List) {
        return Lists.transform((List<V1>) values, function);
      } else {
        return Collections2.transform(values, function);
      }
    }

        return function.apply(value);
      }
    };
  }

  static <K extends @Nullable Object, V1 extends @Nullable Object, V2 extends @Nullable Object>
      Function<V1, V2> asValueToValueFunction(
          final EntryTransformer<? super K, V1, V2> transformer, @ParametricNullness final K key) {
    checkNotNull(transformer);
    return new Function<V1, V2>() {
      @Override

        return function.apply(value);
      }
    };
  }

  static <K extends @Nullable Object, V1 extends @Nullable Object, V2 extends @Nullable Object>
      Function<V1, V2> asValueToValueFunction(
          final EntryTransformer<? super K, V1, V2> transformer, @ParametricNullness final K key) {
    checkNotNull(transformer);
    return new Function<V1, V2>() {
      @Override