text: // generator basics
  
  var genFunc = function* (start) {
      var i = start;
  
      yield i + 1;
      yield i + 2;
      yield i + 3;
  
      return i + 4;
  };
  
  var genObj = genFunc(10);
  
  var result = genObj.next();
  while (!result.done) {
      console.log(`result.value = ${result.value}`);
      result = genObj.next();
  }
  
  console.log(`final result = ${result.value}`);
  
  for (let value of genFunc(100)) {
      console.log(value);
  }
  