eval.c:6295
static VALUE
rb_mod_include(argc, argv, module)
    int argc;
    VALUE *argv;
    VALUE module;
{
    while (argc--) {
	VALUE m = argv[argc];

	Check_Type(m, T_MODULE);
	rb_funcall(m, rb_intern("append_features"), 1, module);
	rb_funcall(m, rb_intern("included"), 1, module);
    }
    return module;
}
