def METHOD_NAME(self, filter=None):
    # Split the namespace with "/" and select the 5th element of the list.
    # 5th element contain yang model name.
    # Remove first 13 characters from model name i.e. ('Cisco-IOS-XR')
    suffix = etree.fromstring(filter[1]).tag.split("/")[5][13:]
    rpc_req_ele = str.join("_", suffix.split("}"))
    return FakeRPCReply(self.find_mocked_data_file(rpc_req_ele))