Index: layer_grp.h
===================================================================
--- layer_grp.h	(revision 28229)
+++ layer_grp.h	(revision 28230)
@@ -278,6 +278,8 @@
 extern const pcb_dflgmap_t pcb_dflg_bot_copper;
 extern const pcb_dflgmap_t pcb_dflg_outline;
 
+/* Overwrite or create all groups from a map */
+void pcb_layergrp_upgrade_by_map(pcb_board_t *pcb, const pcb_dflgmap_t *map);
 
 /* Overwrite an existing group from a default layer group map entry and create
    a layer in the group */