    # File lib/facets/more/timer.rb, line 122
      def limit( time_limit=nil )
        if @time_limit || time_limit
          @current_thread = Thread.current
          @timer_thread = Thread.fork {
            sleep @time_limit
            if @on_timeout then
              @on_timeout.call @time_limit
            else
              @current_thread.raise TimeoutError, "#{@time_limit} seconds past"
            end
          }
        end
      end