code: def _load_json(self):
          
          if os.path.isfile(self.expectations_json):
              self.log.info("Loading expectation config from file {file}".format(file=self.expectations_json))
              return json.load(open(self.expectations_json))
          else:
              self.log.info("Loading expectation config from string")
              return json.loads(self.expectations_json)
docs: Load expectation config based on operator parameters. If provided expectations_json is a file the config will
          be loaded from this file. Otherwise we'll try to load the config as a string.
          :return: