@Override
  public void handshake() throws Exception {
    // Server side, do nothing
  }
Send data in IoTDB based on Opc Ua protocol, using Eclipse Milo. All data are converted into
tablets, and then:

<p>1. In pub-sub mode, converted to eventNodes to send to the subscriber clients.

<p>2. In client-server mode, push the newest value to the local server.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/connector/protocol/opcua/OpcUaConnector.java