+gboolean vik_gps_layer_is_empty ( VikGpsLayer *vgl );
+const GList *vik_gps_layer_get_children ( VikGpsLayer *vgl );
+VikTrwLayer * vik_gps_layer_get_a_child(VikGpsLayer *vgl);
+
+// Non layer specific but expose communal method
+gint vik_gps_comm ( VikTrwLayer *vtl,
+ VikTrack *track,
+ vik_gps_dir dir,
+ gchar *protocol,
+ gchar *port,
+ gboolean tracking,
+ VikViewport *vvp,
+ VikLayersPanel *vlp,
+ gboolean do_tracks,
+ gboolean do_routes,
+ gboolean do_waypoints,
+ gboolean turn_off);
+
+G_END_DECLS
+