def update_params env, json
        env[FORM_HASH] = json
        env[BODY] = env[FORM_INPUT] = StringIO.new(Rack::Utils.build_query(json))
      end
def update_params env, json
        env[FORM_HASH] = json
        env[BODY] = env[FORM_INPUT] = StringIO.new(Rack::Utils.build_query(json))
      end
update all of the parameter-related values in the current request's environment