SCM_CLASS_NEXT_METHOD 2435 src/class.c        SCM_SET_CLASS(nm, SCM_CLASS_NEXT_METHOD);
SCM_CLASS_NEXT_METHOD 2981 src/class.c        BINIT(SCM_CLASS_NEXT_METHOD, "<next-method>", NULL);
SCM_CLASS_NEXT_METHOD 2380 src/gauche.h   #define SCM_NEXT_METHODP(obj)      SCM_XTYPEP(obj, SCM_CLASS_NEXT_METHOD)