public void leaveSomeOutSplit(int index, String filename) {
		List<Bookmark> trainLines = new ArrayList<Bookmark>();
		List<Bookmark> testLines = new ArrayList<Bookmark>();
		int currentUser = -1;
		int userIndex = 0;
		
		Collections.sort(this.reader.getBookmarks());

		int cntUsers=0;
		
		for (Bookmark data : this.reader.getBookmarks()) {
			if (currentUser != data.getUserID())  { // new user
				
				cntUsers++;
				/*if (cntUsers == 500) {
					break;
				}*/
				
				if (userIndex <= index && currentUser != -1) {
				}
				currentUser = data.getUserID();
				userIndex = 0;
			}
			if (++userIndex > index) {
				trainLines.add(data);
			} else {
				testLines.add(data);
			}
		}
		
		writeWikiSample(this.reader, trainLines, filename + "_train", null);
		writeWikiSample(this.reader, testLines, filename + "_test", null);
		trainLines.addAll(testLines);
		writeWikiSample(this.reader, trainLines, filename, null);
	}