docs: def all(self):
          """ Returns list with all indexed identifiers. """
          identifiers = []
  
          query = text("""
              SELECT identifier, type, name
              FROM identifier_index;""")
  
          for result in self.backend.library.database.connection.execute(query):
              vid, type_, name = result
              res = IdentifierSearchResult(
                  score=1, vid=vid, type=type_, name=name)
              identifiers.append(res)
          return identifiers