code: def create_query(self, fields=None):
          
          if fields is None:
              return Query(self.fields)
  
          non_contained_fields = set(fields) - set(self.fields)
          if non_contained_fields:
              raise BaseLunrException(
                  "Fields {} are not part of the index", non_contained_fields
              )
  
          return Query(fields)
docs: Convenience method to create a Query with the Index's fields.
  
          Args:
              fields (iterable, optional): The fields to include in the Query,
                  defaults to the Index's `all_fields`.
  
          Returns:
              Query: With the specified fields or all the fields in the Index.