@property
    def value(self):
        assert self._ready, '_CallbackResult was not set'
        assert isinstance(self._values, tuple) and len(self._values) == 1, (
            '_CallbackResult value is incompatible with set_value_once: %r'
            % (self._values,))

        return self._values[0]
:returns: a reference to the value that was set via `set_value_once`
dataset/ETHPy150Open pika/pika/pika/adapters/blocking_connection.py/_CallbackResult.value