def Rollback(self):
    if not self.in_transaction:
      return
    StatusUpdate('Rolling back the update.')
    self.server.Send('/api/appversion/rollback', app_id=self.app_id,
                     version=self.version)
    self.in_transaction = False
    self.files = {}
Implementation method for set_value. Should return the
dataset/ETHPy150Open CollabQ/CollabQ/.google_appengine/google/appengine/tools/appcfg.py/AppVersionUpload.Rollback--crossover with--dataset/ETHPy150Open enthought/pyface/pyface/ui/wx/grid/composite_grid_model.py/CompositeGridModel._set_value