docs: def _get_generic_schema(self):
          """ Returns whoosh's generic schema of the dataset. """
          schema = Schema(
              vid=ID(stored=True, unique=True),  # Object id
              title=NGRAMWORDS(),
              keywords=KEYWORD,  # Lists of coverage identifiers, ISO time values and GVIDs, source names, source abbrev
              doc=TEXT)  # Generated document for the core of the topic search
          return schema