private void AddSuffixEdge(WordVertex vertex)
{
string suffix = vertex.Word.Substring(1);
WordVertex suffixVertex = GetVertex(suffix, false);
suffixVertex.Add(new FixEdge(vertex.Word[0], Fix.Prefix, vertex));
}
private void AddPrefixEdge(WordVertex vertex)
{
string prefix = vertex.Word.Substring(0, vertex.Word.Length - 1);
WordVertex prefixVertex = GetVertex(prefix, false);
prefixVertex.Add(new FixEdge(vertex.Word[prefix.Length], Fix.Suffix, vertex));
}