@Override
  public void run(R parameter) {
    synchronized (this) {
      result = parameter;
      resultSet = true;
      this.notifyAll();
    }
  }
Called on completion of the RPC call with the response object, or {@code null} in the case of
an error.
@param parameter the response object or {@code null} if an error occurred
hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BlockingRpcCallback.java