def stop
      server = Communist.servers.delete(app.object_id) { |s| NullServer.new }
      if Communist.server.respond_to?(:shutdown)
        server.shutdown
      elsif Communist.server.respond_to?(:stop!)
        server.stop!
      else
        server.stop
      end
      @server_thread.join
    end
def stop
      server = Communist.servers.delete(app.object_id) { |s| NullServer.new }
      if Communist.server.respond_to?(:shutdown)
        server.shutdown
      elsif Communist.server.respond_to?(:stop!)
        server.stop!
      else
        server.stop
      end
      @server_thread.join
    end
Stops the server after handling the connection.
 Attempts to stop the server gracefully, otherwise
 shuts current connection right away.