public Optional<String> findShardingColumn(final String columnName, final String tableName) {
        return Optional.ofNullable(shardingTables.get(tableName)).flatMap(optional -> findShardingColumn(optional, columnName));
    }
@Test
    void assertFindShardingColumnForDefaultTableShardingStrategy() {
        ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
        shardingRuleConfig.getTables().add(createTableRuleConfigWithAllStrategies());
        shardingRuleConfig.setDefaultTableShardingStrategy(new StandardShardingStrategyConfiguration("column", "core_standard_fixture"));
        shardingRuleConfig.getShardingAlgorithms().put("core_standard_fixture", new AlgorithmConfiguration("CORE.STANDARD.FIXTURE", new Properties()));
        Optional<String> actual = new ShardingRule(shardingRuleConfig, createDataSources(), mock(ComputeNodeInstanceContext.class)).findShardingColumn("column", "LOGIC_TABLE");
        assertTrue(actual.isPresent());
        assertThat(actual.get(), is("column"));
    }