pub(crate) fn add_builtin_method_by_str(
        mut self,
        globals: &mut Globals,
        name: &str,
        func: BuiltinFunc,
    ) {
        let name = IdentId::get_id(name);
        self.add_builtin_method(globals, name, func);
    }
Add an instance method `func` named `name` to `self`.
ruruby/src/value/class.rs