public int GetCount(string fragment)
    {
        KNucleotideNode kNucleotideNode;
        ulong           key = CreateKey(fragment);

        if (!frequencies.TryGetValue(key, out kNucleotideNode))
        {
            kNucleotideNode = new KNucleotideNode(0, 0);
        }
        return(kNucleotideNode.V);
    }
    public void KFrequency()
    {
        int n = sequence.Length - length + 1;

        for (int i = frame; i < n; i += length)
        {
            var             key = CreateKey(sequence, i, length);
            KNucleotideNode kNucleotideNode;
            if (frequencies.TryGetValue(key, out kNucleotideNode))
            {
                kNucleotideNode.V++;
            }
            else
            {
                frequencies[key] = new KNucleotideNode(1, length);
            }
        }
    }