Babel bug

class EventEmitter{
  emit(event){
    console.log(event);
  }
}

function emits(obj, prop, descriptor){
  let value;  delete descriptor.writable;
  delete descriptor.value;
  descriptor.get = () => value;
  descriptor.set = (v) => {
    value = v;
    obj.emit(prop + " CHANGE EVENT")
  };
  return descriptor;
}

var objTest = Object.create(EventEmitter.prototype);
EventEmitter.call(objTest);
var descriptor = emits(objTest, 'valueInObject', {});
Object.defineProperty(objTest, 'valueInObject', descriptor);

// Works.  Logs 'valueInObject CHANGE EVENT'
objTest.valueInObject = 10;

class Test extends EventEmitter{
  @emits
  valueInClass;
}

// Does not work.  Throws Error.
new Test().valueInClass = 100;