code: public static boolean areOverlapping(TermOccurrence a, TermOccurrence b) {
  		return a.getSourceDocument().equals(b.getSourceDocument()) && areOffsetsOverlapping(a, b); 
  	}
docs: Returns true if two occurrences are in the same
  document and their offsets overlap.
  
  @param a
  @param b
  @return