var obj = {
  x: 0,
  y: function foo() {
       this.x = "bar";

       function hej() {       // ƒ hej() [[Scopes]][0]: Closure (foo) -> ƒ hej() [[Scopes]][0]: Closure (foo) -> ƒ hej() [[Scopes]][0]: Closure (foo) -> ƒ hej() [[Scopes]][0]: Closure (foo) .......
           this.x = "foo";
           console.dir(hej);
       }
       this.z(hej);
     },
  z: function bam(func) {
       func.call(this);
     }
};
obj.y();