+void Layout3D::add_signal(Signal3D &s)
+{
+ insert_unique(signals, &s.get_signal(), &s);
+}
+
+void Layout3D::remove_signal(Signal3D &s)
+{
+ signals.erase(&s.get_signal());
+}
+
+Signal3D &Layout3D::get_signal(Signal &s) const
+{
+ return *get_item(signals, &s);
+}
+