code: private boolean isInsideMappedRegion(int position,
                                           int startPoint,
                                           int endPoint)
      {
          boolean enclosed = (position < endPoint && position >= startPoint);
          boolean wrapAround = (startPoint > endPoint && (position >= startPoint || position < endPoint)); 
          return enclosed || wrapAround;
      }
docs: Checks whether a given list position is within the partially mapped
  region used for cross-over.
  @param position The list position to check.
  @param startPoint The starting index (inclusive) of the mapped region.
  @param endPoint The end index (exclusive) of the mapped region.
  @return True if the specified position is in the mapped region, false
  otherwise.