public override void VisitCompilationUnit (CompilationUnitSyntax node)
			{
				var startNode = node.DescendantNodesAndSelf (n => region.Start <= n.SpanStart).FirstOrDefault ();
				if (startNode == node || startNode == null) {
					base.VisitCompilationUnit (node);
				} else {
					this.Visit (startNode);
				}
			}