protected function channel($name = null)
    {
        if (!isset(self::channels()[$name])) {
            throw new InvalidCallException("No channel {$name} exists.");
        }

        return call_user_func(self::channels()[$name]);
    }
protected function channel($name = null)
    {
        if (!isset(self::channels()[$name])) {
            throw new InvalidCallException("No channel {$name} exists.");
        }

        return call_user_func(self::channels()[$name]);
    }
protected function channel ( $ name = null ) { if ( ! isset ( self :: channels ( ) [ $ name ] ) ) { throw new InvalidCallException ( "No channel {$name} exists." ) ; } return call_user_func ( self :: channels ( ) [ $ name ] ) ; }
Get a channel instance.

@param  string|null  $name
@return mixed
Get a channel instance .