'This is the callback set on the low-level RPC object.
It sets a flag on the current object indicating that the high-level
callback should now be called.  If interrupts are enabled, it also
interrupts the current wait_any() call by raising an exception.'

def __internal_callback(self):

    self.__must_call_user_callback = True
    self.__rpc.callback = None
    if (self.__class__.__local.may_interrupt_wait and (not self.__rpc.exception)):
        raise apiproxy_errors.InterruptedError(None, self.__rpc)
