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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 register_for_app( self, app_label=None, exclude_models=None, exclude_model_classes=None ):
 """Registers all models for this app_label. """

        models = []
        exclude_models = exclude_models or []
        app_config = django_apps.get_app_config(app_label)
        for model in app_config.get_models():
            if model._meta.label_lower in exclude_models:
                pass
            elif exclude_model_classes and issubclass(model, exclude_model_classes):
                pass
            else:
                models.append(model._meta.label_lower)
        self.register(models)