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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 user_update(auth=None, **kwargs):
    '''
    Update a user

    CLI Example:

    .. code-block:: bash

        salt '*' keystoneng.user_update name=user1 enabled=False description='new description'
        salt '*' keystoneng.user_update name=user1 new_name=newuser
    '''
    cloud = get_openstack_cloud(auth)
    kwargs = _clean_kwargs(**kwargs)
    if 'new_name' in kwargs:
        kwargs['name'] = kwargs.pop('new_name')
    return cloud.update_user(**kwargs)