'Removes configuration attributes of a resource
@param table: the resource DB table
@param keys: keys of attributes to remove (maybe multiple)'

@classmethod
def clear_config(cls, tablename, *keys):

    config = current.model.config
    tn = (tablename._tablename if (type(tablename) is Table) else tablename)
    if (tn in config):
        if (not keys):
            del config[tn]
        else:
            [config[tn].pop(k, None) for k in keys]
    return
