code: def _separate(self, kwargs):
          
          self._pop_none(kwargs)
          result = {}
          for field in Resource.config_fields:
              if field in kwargs:
                  result[field] = kwargs.pop(field)
                  if field in Resource.json_fields:
  
                      # If result[field] is not a string we can continue on
                      if not isinstance(result[field], six.string_types):
                          continue
  
                      try:
                          data = json.loads(result[field])
                          result[field] = data
                      except ValueError:
                          raise exc.TowerCLIError('Provided json file format '
                                                  'invalid. Please recheck.')
          return result
docs: Remove None-valued and configuration-related keyworded arguments