def test_generate_config_image(self):
# Arrange
mailbox = Mailbox('+15555555555', carrier='Foo Wireless')
# Act
with patch('app.models.qrcode') as mock_qrcode:
mailbox.generate_config_image()
# Assert
assert mock_qrcode.make.called
qrcode_json = mock_qrcode.make.call_args[0][0]
self.assertIn('+1555555555', qrcode_json)
self.assertIn('"call_forwarding_set": false', qrcode_json)
self.assertNotIn('_sa_instance_state', qrcode_json)
