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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 get_session(db_url):
 # type: (str) -> Session """Gets SQLAlchemy session given url. Your tables must inherit from Base in hdx.utilities.database. Args: db_url (str):
 SQLAlchemy url Returns: sqlalchemy.orm.session.Session: SQLAlchemy session """

        engine = create_engine(db_url, poolclass=NullPool, echo=False)
        Session = sessionmaker(bind=engine)
        Base.metadata.create_all(engine)
        return Session()