Websocket's listeners are ingored?

I'm facing a strange situation: after changing the code, the event listeners are not registered anymore.

The code now looks like:

MyClass.prototype.initialize = function () {
    var self = this;
    self.wifi.connect( self.ssid, { password:self.wlanPw }, function( err ){
      console.log( "connected? info=", self.wifi.getIP() );
      if( !err ) self.connect();
    } );
}

MyClass.prototype.connect = function () {
	this.ws = new WS( this.serverHost, { port:8822 } );
	this.ws.gwId = this.wifi.getIP().mac;
	this.ws.premiseId = this.premiseId;
	this.ws.handshake = this.handshake.bind( this.ws );
	this.ws.on( 'open', function(){
	  console.log( 'ws openned' );
	} );
	this.ws.on( 'message', this.onWsMessage );
	this.ws.on( 'close', this.onWsClose );

	console.log( "Connecting to ", this.serverHost, 8822 );
};

MyClass.prototype.onWsMessage = function( msg ) { doSomething(); };
MyClass.prototype.onWsClose = function() { ... };

in the console I see

connected? info= {
"ip": "192.168.0.16",
"netmask": "255.255.255.0",
"gw": "192.168.0.1",
"mac": "5c:cf:7f:19:71:73"
}
Connecting to ec2-52-34-212-117.us-west-2.compute.amazonaws.com 8822

I see also, that the WS request hits the server.

It used to work, so now I'm banging my head trying to figure out what could possibly go wrong here...