def read_query_values(self, prop_query_name, prop_query_values):
        prop_handler = self.get_property_handler(prop_query_name)

        if(not prop_handler.can_query()):
            raise KeyError("Can not filter on property %s" % prop_query_name)

        return (prop_handler.get_query_field(),
                [self.read_query_value(prop_handler, v)
                 for v in prop_query_values])
Returns a tuple of (query_field, query_values) from the given
dataset/ETHPy150Open jahlborn/appengine-rest-server/src/main/python/rest/__init__.py/ModelHandler.read_query_values