public Optional<RouteMapper> findTableMapper(final String logicDataSourceName, final String actualTableName) {
        for (RouteUnit each : routeUnits) {
            Optional<RouteMapper> result = each.findTableMapper(logicDataSourceName, actualTableName);
            if (result.isPresent()) {
                return result;
            }
        }
        return Optional.empty();
    }
@Test
    void assertFindTableMapper() {
        Optional<RouteMapper> actual = multiRouteContext.findTableMapper(DATASOURCE_NAME_1, ACTUAL_TABLE);
        assertTrue(actual.isPresent());
        assertThat(actual.get(), is(new RouteMapper(LOGIC_TABLE, ACTUAL_TABLE)));
    }