question: private void connectToRoomInternal ( ) { this . roomState = ConnectionState . NEW ; String endpoint = connectionParameters . roomId ; Matcher matcher = IP_PATTERN . matcher ( endpoint ) ; if ( ! matcher . matches ( ) ) { reportError ( "roomId must match IP_PATTERN for DirectRTCClient." ) ; return ; } String ip = matcher . group ( 1 ) ; String portStr = matcher . group ( matcher . groupCount ( ) ) ; int port ; if ( portStr != null ) { try { port = Integer . parseInt ( portStr ) ; } catch ( NumberFormatException e ) { reportError ( "Invalid port number: " + portStr ) ; return ; } } else { port = DEFAULT_PORT ; } tcpClient = new TCPChannelClient ( executor , this , ip , port ) ; }
target:  Connects to the room. Runs on the looper thread.