code: func (j *Json) GetIndex(index int) *Json {
  	a, err := j.Array()
  	if err == nil {
  		if len(a) > index {
  			return &Json{a[index]}
  		}
  	}
  	return &Json{nil}
  }
docs: // GetIndex returns a pointer to a new `Json` object
  // for `index` in its `array` representation
  //
  // this is the analog to Get when accessing elements of
  // a json array instead of a json object:
  //    js.Get("top_level").Get("array").GetIndex(1).Get("key").Int()