code: def revoke_token(self, subid):
      '''revoke a token by removing it. Is done at finish, and also available
      as a command line option'''
      from expfactory.database.models import Participant
      p = Participant.query.filter(Participant.id == subid).first()
      if p is not None:
          p.token = 'revoked'
      self.session.commit()
      return f revoke_token(self, subid):
      '''revoke a token by removing it. Is done at finish, and also available
      as a command line option'''
      from expfactory.database.models import Participant
      p = Participant.query.filter(Participant.id == subid).first()
      if p is not None:
          p.token = 'revoked'
      self.session.commit()
      return p
docs: revoke a token by removing it. Is done at finish, and also available
      as a command line option