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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 setup_user_manager(app):
 """Setup flask-user manager."""


    from flask_user import SQLAlchemyAdapter

    from rio.models import User

    init = dict(
        db_adapter=SQLAlchemyAdapter(db, User),
    )
    user_manager.init_app(app, **init)