Updated Generic Nodes to be Uninstantiable

C#/Datastructures/Generic/DirectedNode.cs

@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace C_.Datastructures.Generic
 {
-    internal class DirectedNode<T, NodeType>
+    abstract internal class DirectedNode<T, NodeType>
     {
         public T? Value { get; set; } = default;
         public NodeType? Left { get; set; } = default;

C#/Datastructures/Generic/UndirectedNode.cs

@@ -1,6 +1,6 @@
 namespace C_.Datastructures.Generic
 {
-    internal class UndirectedNode<T, NodeType>
+    abstract internal class UndirectedNode<T, NodeType>
     {//Generic Node type that every other type inherits from
         public T? Value { get; set; } = default;
         public NodeType? Next { get; set; } = default;