visad/src/main/java/ucar/nc2/iosp/grid/GridIndex.java
public void finish() {
    if (gcs.size() == 1)
      return;
    if (gcs.size() == 2) {
      List hcs = getHorizCoordSys();
      GridDefRecord.compare((GridDefRecord) hcs.get(0), (GridDefRecord) hcs.get(1));
    }
  }
public void finish() {
    if (gcs.size() == 1)
      return;
    if (gcs.size() == 2) {
      List hcs = getHorizCoordSys();
      GridDefRecord.compare((GridDefRecord) hcs.get(0), (GridDefRecord) hcs.get(1));
    }
  }
compares GDS for duplicates