code: def get_candidate_config(self, merge=False, formal=False):
          
          command = "show configuration"
          if merge:
              command += " merge"
          if formal:
              command += " formal"
          response = self._execute_config_show(command)
  
          match = re.search(".*(!! IOS XR Configuration.*)$", response, re.DOTALL)
          if match is not None:
              response = match.group(1)
  
          return response
docs: Retrieve the configuration loaded as candidate config in your configuration session.
  
          :param merge:  Merge candidate config with running config to return
                         the complete configuration including all changed
          :param formal: Return configuration in IOS-XR formal config format