code: def ungrounded_texts(stmts):
      ungrounded = [ag.db_refs['TEXT']
                    for s in stmts
                    for ag in s.agent_list()
                    if ag is not None and list(ag.db_refs.keys()) == ['TEXT']]
      ungroundc = Counter(ungrounded)
      ungroundc = ungroundc.items()
      ungroundc = sorted(ungroundc, key=lambda x: x[1], reverse=True)
      return ungroundc