fn teq(vm: &mut VM, self_val: Value, args: &Args2) -> VMResult {
    args.check_args_num(1)?;
    let class = vm.globals.get_class(vm[0]);
    let self_val = self_val.into_module();
    Ok(Value::bool(class.include_module(self_val)))
}
## instance method Module#===
- self === obj -> bool

https://docs.ruby-lang.org/ja/latest/method/Module/i/=3d=3d=3d.html
ruruby/src/builtin/module.rs