code: public void appendOutBuffer(Object obj, byte[] data, int offset, int len, boolean close) {
          if (len > 0) {
              collector().appendOutBuffer(getRuleName(), obj, data, offset, len);
          }
          if (close) {
              collector().recordOutBuffer(getRuleName(), obj);
          }
      }
docs: This method appends data to the buffer associated with the supplied object.
  
  @param obj The object associated with the buffer
  @param data The data to be appended
  @param offset The offset of the data
  @param len The length of data
  @param close Whether to close the buffer after appending the data