def try_long_poll(routing_keys, event_uuids, &handler)
      begin
        long_poll(routing_keys, event_uuids, &handler)
      rescue Exception => e
        e
      end
    end
def try_long_poll(routing_keys, event_uuids, &handler)
      begin
        long_poll(routing_keys, event_uuids, &handler)
      rescue Exception => e
        e
      end
    end
Try to make long-polling request to receive events

 @param [Array, NilClass] routing_keys for event sources of interest with nil meaning all
 @param [Array, NilClass] event_uuids from previous poll

 @yield [event] required block called each time event received
 @yieldparam [Hash] event received

 @return [Array, NilClass, Exception] UUIDs of events received, or nil if none, or Exception if failed