* @return The frequency is stored inside an ArrayList<Count> of size=1.
*/
public ArrayList<Count> getCounts(String lemma) {
int i=Collections.binarySearch(wordCounts,lemma);
ArrayList<Count> counts=new ArrayList<Count>();
Count c;
if(i>=0)
c=new Count(Double.parseDouble(wordCounts.get(i).getString()),this.name);
else
c=new Count(0.0,this.name);
counts.add(c);
return counts;
}