public FastNode(FastNode parent,char letter) : base(parent,letter)
 {
     Children = new Dictionary<char, FastNode>();
 }
 public INode AddChild(char letter)
 {
     FastNode n = new FastNode(this, letter);
     Children.Add(letter, n);
     return n;
 }
 public FastWordTree(FastNode root, string filename) :base(root,filename)
 {
 }