    # File lib/rfilter/delivery_agent.rb, line 177
        def pipe(command, continue = false)
          log(2, "Action: pipe to #{command.inspect}")
          deliver_pipe(command, @message)
          if $? != 0
            m = "pipe failed for command #{command.inspect}"
            log(1, "Error: " + m)
            raise DeliveryCommandFailure.new(m, $?)
          end
          unless continue
            raise DeliverySuccess.new("pipe to #{command.inspect}")
          end
        end