code: func Map(array []interface{}, iterator ResultIterator) []interface{} {
  	var result = make([]interface{}, len(array))
  	for index, data := range array {
  		result[index] = iterator(data, index)
  	}
  	return result
  }
docs: // Map iterates over the slice and apply ResultIterator to every item. Returns new slice as a result.