publish method
Implementation
publish(ChabokMessage message) {
var msgMap = <String, dynamic> {
'userId': message.userId,
'content': message.content
};
if (message.channel != null) {
msgMap['channel'] = message.channel;
}
if (message.data != null) {
msgMap['data'] = message.data;
}
if (message.notification != null) {
msgMap['notification'] = message.notification;
}
_channel.invokeMethod("publish", msgMap);
}