public override int GetHashCode() { unchecked { var hashCode = Vertex1 != null?Vertex1.GetHashCode() : 0; hashCode = (hashCode * 397) ^ (Vertex2 != null ? Vertex2.GetHashCode() : 0); hashCode = (hashCode * 397) ^ (Vertex3 != null ? Vertex3.GetHashCode() : 0); return(hashCode); } }