join method
Join this channel using the associated PhoenixSocket.
Implementation
Push join([Duration? newTimeout]) {
assert(!_joinedOnce);
if (newTimeout != null) {
_timeout = newTimeout;
}
_joinedOnce = true;
if (socket.isConnected) {
_attemptJoin();
} else {
_state = PhoenixChannelState.errored;
}
return _joinPush;
}