code: public boolean compare(List<CoreLabel> doc1, List<CoreLabel> doc2) {
  		int i1 = 0, i2 = 0; //
  		String last1 = "O", last2 = "O";
  
  		boolean cm_set;
  	
  		for (int i = 0; i < doc1.size(); i++) {
  			CoreLabel c1 = doc1.get(i);
  			CoreLabel c2 = doc2.get(i);
  			
  			String a1 = c1.getString(AnswerAnnotation.class);
  			String a2 = c2.getString(AnswerAnnotation.class);
  			
  			if (a1 == null || a2 == null) return false;
  		}
  		// TODO
  			
  		return true;
  	}
docs: Compare two classifier output
  @param doc1
  @param doc2
  @return