channel.go
func (ch *Channel) State() ChannelState {
	ch.mutable.RLock()
	state := ch.mutable.state
	ch.mutable.RUnlock()

	return state
}
func (ch *Channel) State() ChannelState {
	ch.mutable.RLock()
	state := ch.mutable.state
	ch.mutable.RUnlock()

	return state
}
// State returns the current channel state.