extract_grob_set (me, "stems", stems);
Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
extract_grob_set (me, "stems", stems);
Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);