code: @Override
      public void write(DataOutput out)
              throws IOException {
          ensureTextSet();
          // Write a variable int with the length
          WritableUtils.writeVInt(out, _text.limit());
          // Write the bytes.  For efficiency directly access the buffer's array.
          out.write(_text.array(), 0, _text.limit());
      }
docs: Writes this instance's content to the output.  Note that the format for Row is identical to Text, so even though
  the classes are unrelated a Text object can read the bytes written by a Row as a JSON string.