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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def assert_instance_created(self, model_class, **kwargs):
 """ Checks if a model instance was created in the database. For example:: """

        return _InstanceContext(
            self.assert_instance_does_not_exist,
            self.assert_instance_exists,
            model_class,
            **kwargs
        )