bufr/src/main/java/ucar/nc2/iosp/bufr/DataDescriptor.java
private int getListHash() {
    if (subKeys == null) return 0;
    int result = 1;
    for (DataDescriptor e : subKeys)
      result = 31*result + (e==null ? 0 : e.hashCode2());
    return result;
  }
private int getListHash() {
    if (subKeys == null) return 0;
    int result = 1;
    for (DataDescriptor e : subKeys)
      result = 31*result + (e==null ? 0 : e.hashCode2());
    return result;
  }
has to use hashCode2, so cant use list.hashCode()