marshal.c:369
static void
w_class(type, obj, arg)
    int type;
    VALUE obj;
    struct dump_arg *arg;
{
    char *path;

    VALUE klass = CLASS_OF(obj);
    w_extended(klass, arg);
    w_byte(type, arg);
    path = rb_class2name(klass);
    w_unique(path, arg);
}
