code: def cascade_delete(self, name):
      "this fails under diamond inheritance"
      for child in self[name].child_tables:
        self.cascade_delete(child.name)
      del self[namef cascade_delete(self, name):
      "this fails under diamond inheritance"
      for child in self[name].child_tables:
        self.cascade_delete(child.name)
      del self[name]
docs: this fails under diamond inheritance