@classmethod
def get_mobile_grid_key(cls):
    """
        Must return a unique "config key" for the mobile grid, for sort/filter
        purposes etc.  (It need only be unique among *mobile* grids.)  Instead
        of overriding this, you can set :attr:`mobile_grid_key`.  Default is
        the value returned by :meth:`get_route_prefix()`.
        """
    if hasattr(cls, 'mobile_grid_key'):
        return cls.mobile_grid_key
    return 'mobile.{}'.format(cls.get_route_prefix())
