public Edge(Vertex from, Vertex to, ParticleType type)
{
// if (type.IsAntiParticle())
/// {
// (from, to) = (to, from);
// type = type.AntiParticle();
// }
this.From = from;
From.AddEdge(this);
this.To = to;
To.AddEdge(this);
this.ParticleType = type;
}