public List<String> createMismatches(String s) {
        List<String> mismatchList = new ArrayList();
        List<String> helpList;
        int stringLength = s.length();

        for (int i = 0; i < stringLength; i++) {
            Character ch = s.charAt(i);
            helpList = changeChar(s, i, ch);
            for (String string : helpList) {
                if (!existsInList(mismatchList, string)) {
                    mismatchList.add(string);
                }
            }
        }

        mismatchList.add(s);

        return mismatchList;
    }