code: private void ensureFill() throws JedisConnectionException {
      if (count >= limit) {
        try {
          limit = in.read(buf);
          count = 0;
          if (limit == -1) {
            throw new JedisConnectionException("Unexpected end of stream.");
          }
        } catch (IOException e) {
          throw new JedisConnectionException(e);
        }
      }
    }
docs: This methods assumes there are required bytes to be read. If we cannot read anymore bytes an
  exception is thrown to quickly ascertain that the stream was smaller than expected.