public override void OnImport(Import node)
{
// this is a bit nasty - get all the members of the referenced namespace
// then push them on the tree, so they're referencable
var ns = (INamespace)TypeSystemServices.GetEntity(node);
currentDocument.Imports[node.Namespace] = new ImportedNamespaceTreeNode(new EntitySourceOrigin((IEntity)ns));
base.OnImport(node);
}