'make sure the add on open error callback is added'

def test_add_on_open_error_callback(self):

    self.connection.callbacks = mock.Mock(spec=self.connection.callbacks)
    self.connection.add_on_open_error_callback(callback_method)
    self.connection.callbacks.remove.assert_called_once_with(0, self.connection.ON_CONNECTION_ERROR, self.connection._on_connection_error)
    self.connection.callbacks.add.assert_called_once_with(0, self.connection.ON_CONNECTION_ERROR, callback_method, False)
