/// <summary> /// Represents the subtype relation "subType <: superType". /// This means that values of type subType can be assigned to variables of type superType. /// </summary> public NullabilityEdge(NullabilityNode source, NullabilityNode target, EdgeLabel label) { this.Source = source ?? throw new ArgumentNullException(nameof(source)); this.Target = target ?? throw new ArgumentNullException(nameof(target)); this.Label = label; }