private void serializeBands(final MeterBandHeaders meterBandHeaders, final ByteBuf outBuffer) {
if (meterBandHeaders != null && meterBandHeaders.getMeterBandHeader() != null) {
- meterBandHeaders.getMeterBandHeader().forEach(meterBandHeader ->
+ meterBandHeaders.nonnullMeterBandHeader().values().forEach(meterBandHeader ->
Optional.ofNullable(meterBandHeader.getMeterBandTypes())
.flatMap(m -> Optional.ofNullable(m.getFlags()))
.ifPresent(flags -> Optional.ofNullable(meterBandHeader.getBandType()).ifPresent(type -> {