public static IoTDBConfigNodeReceiverAgent receiver() {
    return PipeConfigNodeAgentHolder.HANDLE.pipeConfigNodeReceiverAgent;
  }
Get the singleton instance of {@link IoTDBConfigNodeReceiverAgent}.

@return the singleton instance of {@link IoTDBConfigNodeReceiverAgent}
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/pipe/agent/PipeConfigNodeAgent.java