docs: public <V> V convertFrom(final char[] text, final int start, final int len) {
          if (text == null) return null;
          final JsonReader in = readerPool.get();
          in.setText(text, start, len);
          Object rs = new AnyDecoder(factory).convertFrom(in);
          readerPool.accept(in);
          return (V) rs;
      }