join method Null safety

Push join(
  1. [Duration? newTimeout]
)

Join this channel using the associated PhoenixSocket.

Implementation

Push join([Duration? newTimeout]) {
  assert(!_joinedOnce);

  if (newTimeout != null) {
    _timeout = newTimeout;
  }

  _joinedOnce = true;
  _attemptJoin();

  return _joinPush;
}