Cycle race track lap counter

OK - found the solution myself.
This works:

var Obj = {
    message: "foo",

    init: function() {
        this.message = "foo";
        setInterval(()=>{
          this.log();
        }, 1000);
    },

    log: function() {
        console.log(this.message);
    }
};

Obj.init();

Something about scope and references I guess.