public static String getDatabaseRuleNode(final String databaseName, final String ruleName, final String key) {
        return String.join("/", getDatabaseRuleNode(databaseName, ruleName), key);
    }
@Test
    void assertGetDatabaseRuleNode() {
        assertThat(DatabaseRuleMetaDataNode.getDatabaseRuleNode("foo_db", "foo_rule", "sharding"), is("/metadata/foo_db/rules/foo_rule/sharding"));
    }