code: def validate(self, obj_to_validate, is_substitute=True):
          
          res = []
          for check in self.__cfg[Validator.__CFG_KEY_CHECKS]:
              self.__logger.info('Performing {} validation against {}'.format(check, obj_to_validate))
              check_res = Check(self.__cfg[Validator.__CFG_KEY_CHECKS][check]).validate(obj_to_validate, is_substitute)
              if check_res:
                  if type(check_res) == dict:
                      res.append(check_res)
                  else:
                      res.extend(check_res)
          return None if len(res) == 0 else res
docs: Performs validation
          :param obj_to_validate:
          :param is_substitute:
          :return: list of validation messages or None