'Test if backend specific checks are performed.'

@mock.patch('django.db.models.fields.router.allow_migrate', new=dummy_allow_migrate)
def test_check_field(self):

    error = Error('an    error')
    class Model(models.Model, ):
        field = models.IntegerField()
    field = Model._meta.get_field('field')
    with mock.patch.object(connections['default'].validation, 'check_field', return_value=[error]):
        self.assertEqual(field.check(), [error])
