docs: public static void writeString(String value, ByteBuffer buf) {
          if (value == null) {
              buf.putInt(VoltType.NULL_STRING_LENGTH);
              return;
          }
  
          byte[] strbytes = value.getBytes(Constants.UTF8ENCODING);
          int len = strbytes.length;
  
          buf.putInt(len);
          buf.put(strbytes);
      }