def unsubscribe(channel, _json_data)
      log_debug "#{self.class} runs 'unsubscribe' method with  #{channel}"
      return unless channel.present?
      forget_channel(channel)
      delete_server_subscribers(channel)
    end
def unsubscribe(channel, _json_data)
      log_debug "#{self.class} runs 'unsubscribe' method with  #{channel}"
      return unless channel.present?
      forget_channel(channel)
      delete_server_subscribers(channel)
    end
the method will unsubscribe a client by closing the websocket connection if has unscribed from all channels
 and deleting the reactor from the channel list on the server

 @param [String] channel

 @return [void]

 @api public