# File lib/rack/request.rb, line 235
    def update_param(k, v)
      found = false
      if self.GET.has_key?(k)
        found = true
        self.GET[k] = v
      end
      if self.POST.has_key?(k)
        found = true
        self.POST[k] = v
      end
      unless found
        self.GET[k] = v
      end
      @params = nil
      nil
    end