@Override
    public String toString(final RouteUnit routeUnit) {
        return identifier.getQuoteCharacter().wrap(getConstraintValue(routeUnit));
    }
@Test
    void assertToString() {
        assertThat(new ConstraintToken(0, 1, new IdentifierValue("uc"),
                mock(SQLStatementContext.class, withSettings().extraInterfaces(TableAvailable.class).defaultAnswer(RETURNS_DEEP_STUBS)), mock(ShardingRule.class)).toString(getRouteUnit()), is("uc"));
    }