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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_user_models(user_models, admin=None, schema=None):
 """Register any user-defined models with the API Service. :param list user_models: A list of user-defined models to include in the API service """

    if any([issubclass(cls, AutomapModel) for cls in user_models]):
        AutomapModel.prepare(  # pylint:disable=maybe-no-member
                               db.engine, reflect=True, schema=schema)

    for user_model in user_models:
        register_model(user_model, admin)