internal virtual Tree GetParent(Tree node)
{
if (node is IHasParent)
{
return(node.Parent());
}
if (nodesToParents == null)
{
nodesToParents = new IdentityHashMap <Tree, Tree>();
}
if (nodesToParents.IsEmpty())
{
FillNodesToParents(root, null);
}
return(nodesToParents[node]);
}
/// <summary>Returns <code>true</code> if this set contains no elements.</summary>
/// <returns><code>true</code> if this set contains no elements.</returns>
public override bool IsEmpty()
{
return(map.IsEmpty());
}
