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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 save(self, obj):
 """Add ``obj`` to the SQLAlchemy session and commit the changes back to the database. :param obj: SQLAlchemy object being saved :returns: The saved object """

        session = self.get_db_session()
        session.add(obj)
        session.commit()

        return obj