code: static <K, V1, V2> Function<Entry<K, V1>, V2> asEntryToValueFunction(
        final EntryTransformer<? super K, ? super V1, V2> transformer) {
      checkNotNull(transformer);
      return new Function<Entry<K, V1>, V2>() {
        @Override
        public V2 apply(Entry<K, V1> entry) {
          return transformer.transformEntry(entry.getKey(), entry.getValue());
        }
      };
    }
docs: Views an entry transformer as a function from {@code Entry} to values.