protected void reduce(final PlumeObject arg0, java.lang.Iterable<PlumeObject> values,
Reducer<PlumeObject, PlumeObject, PlumeObject, PlumeObject>.Context context)
throws IOException, InterruptedException {
PCollection col = mscr.getChannelByNumber().get(arg0.sourceId);
OutputChannel oC = mscr.getOutputChannels().get(col);
if(oC.combiner != null) {
// Apply combiner function for this channel
List<WritableComparable> vals = Lists.newArrayList();
for(PlumeObject val: values) {
vals.add(val.obj);