code: func (q *BytesQueue) peekCheckErr(index int) error {
  
  	if q.count == 0 {
  		return errEmptyQueue
  	}
  
  	if index <= 0 {
  		return errInvalidIndex
  	}
  
  	if index+headerEntrySize >= len(q.array) {
  		return errIndexOutOfBounds
  	}
  	return nil
  }
docs: // peekCheckErr is identical to peek, but does not actually return any data