code: static <V2, K, V1> Entry<K, V2> transformEntry(
        final EntryTransformer<? super K, ? super V1, V2> transformer, final Entry<K, V1> entry) {
      checkNotNull(transformer);
      checkNotNull(entry);
      return new AbstractMapEntry<K, V2>() {
        @Override
        public K getKey() {
          return entry.getKey();
        }
  
        @Override
        public V2 getValue() {
          return transformer.transformEntry(entry.getKey(), entry.getValue());
        }
      };
    }
docs: Returns a view of an entry transformed by the specified transformer.