default ClickHouseRecord firstRecord() {
        return records().iterator().next();
    }
Gets the first record only. Please use {@link #records()} instead if you need
to access the rest of records.

@return the first record
@throws NoSuchElementException when there's no record at all
@throws UncheckedIOException   when failed to read data(e.g. deserialization)
clickhouse-client/src/main/java/com/clickhouse/client/ClickHouseResponse.java