public void addNewOccurrence(String document) {
        //Duplicate checking
        boolean add = true;
        for(Occurrence occ: docsList.toArray()){
            if(occ.getDocName().compareTo(document) == 0){
                add = false;
                occ.incFrequency();
            }
        }

        if(add){
            docsList.insert(document);
            incFrequency();

        }
    }