code: def remove(self, rev, permanent=False):
          
          if not isinstance(rev, Revision):
              raise TypeError('argument needs to be an instance of Revision')
  
          if rev not in self:
              raise ValueError('{} not in changelist'.format(rev))
  
          self._files.remove(rev)
          if not permanent:
              rev.changelist = self._connection.default
docs: Removes a revision from this changelist
  
          :param rev: Revision to remove
          :type rev: :class:`.Revision`
          :param permanent: Whether or not we need to set the changelist to default
          :type permanent: bool