@Override
    public String toString(final RouteUnit routeUnit) {
        return identifier.getQuoteCharacter().wrap(getConstraintValue(routeUnit));
    }
@Test
    void assertUpperCaseToString() {
        SQLStatementContext sqlStatementContext = mockSQLStatementContext();
        assertThat(new ConstraintToken(0, 1, new IdentifierValue("uc"), sqlStatementContext, mock(ShardingRule.class)).toString(getRouteUnit()), is("uc_t_order_0"));
    }