# File lib/core/connection_driver.rb, line 118
    def tick(now=Time.now)
      transport = Cproton.pni_connection_driver_transport(@impl)
      ms = Cproton.pn_transport_tick(transport, (now.to_r * 1000).to_i)
      return ms.zero? ? nil : Time.at(ms.to_r / 1000);
    end