@Override
    public ResultSet getFunctions(final String catalog, final String schemaPattern, final String functionNamePattern) throws SQLException {
        return createDatabaseMetaDataResultSet(getDatabaseMetaData().getFunctions(getActualCatalog(catalog), getActualSchema(schemaPattern), functionNamePattern));
    }
@Test
    void assertGetFunctions() throws SQLException {
        when(databaseMetaData.getFunctions("test", null, null)).thenReturn(resultSet);
        assertThat(shardingSphereDatabaseMetaData.getFunctions("test", null, null), instanceOf(DatabaseMetaDataResultSet.class));
    }