This method sends a command to the server.
async xmpp.sendCommand(command : string): Promise<void>
The SendCommand method will send the Command parameter to the server. The command must be in valid XML format, and must be recognizable to the IMServer.
The SendCommand method should only be used by programmers or users who are connecting to non-standard servers whose command list is not covered by the class. Any responses that are defined in the protocol specification will be returned by the appropriate event. Any non-standard IQ message will be returned by the IQ event. All other responses will be returned by the PITrail event.