code: def select(self, Class, set=None, recursive=True,  ignore=True):
          
          if self.mode == Mode.MEMORY:
              for t in self.data:
                  if Class.__name__ == 'Text':
                      yield t
                  else:
                      for e in t.select(Class,set,recursive,ignore):
                          yield e
docs: See :meth:`AbstractElement.select`