code: public static <K,V> Optional<V> getOpt(Map<K,V> map, K key) {
          return Optional.ofNullable(map.get(key));
      }
docs: Get an item from a map, wrapping it in an Optional
  @param map the map on which to perform the lookup
  @param key the key to look up
  @param <K> the type of key
  @param <V> the type of values in the map
  @return Optional-wrapped V