Hi,

Is there a way to implement the "CreateNode" method in my library abstract below? Or can this only be done in client code outside the library? I current get the error "Cannot create an instance of the abstract class or interface 'ToplogyLibrary.AbstractNode"

public abstract class AbstractTopology<T>
{
    // Properties
    public Dictionary<T, AbstractNode<T>> Nodes { get; private set; }
    public List<AbstractRelationship<T>> Relationships { get; private set; }

    // Constructors
    protected AbstractTopology()
    {
        Nodes = new Dictionary<T, AbstractNode<T>>();
    }

    // Methods
    public AbstractNode<T> CreateNode()
    {
        var node = new AbstractNode<T>();  // ** Does not work **
        Nodes.Add(node.Key, node);
        }
    }
 }

    public abstract class AbstractNode<T>
    {
        public T Key { get; set; }
    }

    public abstract class AbstractRelationship<T>
    {
        public AbstractNode<T> Parent { get; set; }
        public AbstractNode<T> Child { get; set; }

    }