code: func (iter Enumerator) Select(transform Transform) Enumerator {
  	retval := make(chan interface{})
  
  	go func() {
  		for item := range iter {
  			retval <- transform(item)
  		}
  		close(retval)
  	}()
  
  	return retval
  }
docs: // Select iterates over a list and returns a transformed item.