code: def parse_form_request(api_secret, request):
      
      if not check_sign(api_secret, request):
          raise SignError(u"message sign error")
  
      return Storage(request)
docs: >>> parse_form_request("123456",{"nonce": 1451122677, "msg": "helllo", "code": 0, "sign": "DB30F4D1112C20DFA736F65458F89C64"})
          <Storage {'nonce': 1451122677, 'msg': 'helllo', 'code': 0, 'sign': 'DB30F4D1112C20DFA736F65458F89C64'}>