@Override
  public int compareTo(@NotNull final ChainOpAndOccurrences that) {
    final int sub = -getOccurrenceCount() + that.getOccurrenceCount();
    if (sub != 0) {
      return sub;
    }
    return myOp.hashCode() - that.myOp.hashCode();
  }
@Override
  public int compareTo(@NotNull final ChainOpAndOccurrences that)