@Override
    public String convert(final SingleRuleConfiguration ruleConfig) {
        if (ruleConfig.getTables().isEmpty() && !ruleConfig.getDefaultDataSource().isPresent()) {
            return "";
        }
        StringBuilder result = new StringBuilder();
        if (!ruleConfig.getTables().isEmpty()) {
            result.append(convertLoadTable(ruleConfig));
        }
        if (ruleConfig.getDefaultDataSource().isPresent()) {
            if (!ruleConfig.getTables().isEmpty()) {
                result.append(System.lineSeparator()).append(System.lineSeparator());
            }
            result.append(convertSetDefaultSingleTableStorageUnit(ruleConfig.getDefaultDataSource().get()));
        }
        return result.toString();
    }
@Test
    void assertConvert() {
        SingleRuleConfiguration singleRuleConfig = new SingleRuleConfiguration(new LinkedList<>(Arrays.asList("t_0", "t_1")), "foo_ds");
        SingleRuleConfigurationToDistSQLConverter singleRuleConfigurationToDistSQLConverter = new SingleRuleConfigurationToDistSQLConverter();
        assertThat(singleRuleConfigurationToDistSQLConverter.convert(singleRuleConfig),
                is("LOAD SINGLE TABLE t_0,t_1;" + System.lineSeparator() + System.lineSeparator() + "SET DEFAULT SINGLE TABLE STORAGE UNIT = foo_ds;"));
    }