code: func (p *PortList) Pop() string {
  	if len(*p) == 0 {
  		panic("list is empty")
  	}
  	val := (*p)[len(*p)-1]
  	*p = (*p)[:len(*p)-1]
  	return val
  }
docs: // Pop returns a value from the list, it panics if the value is not there