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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 update_user_display_name(user,**kwargs):
 """ Update a user's display name """

    #check_perm(kwargs.get('user_id'), 'edit_user')
    try:
        user_i = db.DBSession.query(User).filter(User.id==user.id).one()
        user_i.display_name = user.display_name
        return user_i
    except NoResultFound:
        raise ResourceNotFoundError("User (id=%s) not found"%(user.id))