@Override
	public LinkedList<String> getIcebergs() {

		// To limit the number of false positive, we select only words with more
		// than 1 occurrence
		// (words that occurred at least 2 times within the last 1/frequency
		// words read).
		LinkedList<String> l = new LinkedList<String>();
		
		for (String s : sample.keySet())
			if (sample.get(s) > 1)
				l.add(s);
		
		return l;
	}