code: @Override
      public void readFields(DataInput in) throws IOException {
          int ordinal = in.readInt();
          contentType = ContentType.valueOf(ordinal);
          int length = WritableUtils.readVInt(in);
          if (length > MAX_BUFFER_SIZE) {
              is = (DataInputStream)in;
              return;
          }
          content = new byte[length];
          in.readFully(content, 0, length);
      }
docs: /* (non-Javadoc)
  @see com.marklogic.mapreduce.MarkLogicDocument#readFields(java.io.DataInput)