grib/src/main/java/ucar/nc2/grib/collection/PartitionCollectionMutable.java
void addPartition(int partno, int groupno, int varno, int ndups, int nrecords, int nmissing,
        GribCollectionMutable.VariableIndex vi) {
      if (partList == null) partList = new ArrayList<>(nparts);
      partList.add(new PartitionForVariable2D(partno, groupno, varno));
      this.ndups += ndups;
      this.nrecords += nrecords;
      this.nmissing += nmissing;
    }
void addPartition(int partno, int groupno, int varno, int ndups, int nrecords, int nmissing,
        GribCollectionMutable.VariableIndex vi) {
      if (partList == null) partList = new ArrayList<>(nparts);
      partList.add(new PartitionForVariable2D(partno, groupno, varno));
      this.ndups += ndups;
      this.nrecords += nrecords;
      this.nmissing += nmissing;
    }
only used by PartitionBuilder, not PartitionBuilderFromIndex