def assign_new(params, new_params)
      new_params.each_pair do |name, value|
        if value.is_a?(Hash)
          assign_new(params.get(name), value)
        else
          # assign
          params.set(name, value)
        end
      end
    end
def assign_new(params, new_params)
      new_params.each_pair do |name, value|
        if value.is_a?(Hash)
          assign_new(params.get(name), value)
        else
          # assign
          params.set(name, value)
        end
      end
    end
Assign any new params, which weren't in the old params.