code: func (l *List) Get(pos uint) (interface{}, bool) {
  	l.key.RLock()
  	defer l.key.RUnlock()
  
  	if pos > uint(len(l.underlyer)) {
  		return nil, false
  	}
  	return l.underlyer[pos], true
  }
docs: // Get retreives the value stored in a particular position of the list.
  // If no item exists at the given position, the second parameter will be
  // returned as false.