text: [System.Collections.ArrayList]$queue = @()
  # isEmpty?
  if ($queue.Count -eq 0) {
      "isEmpty? result : the queue is empty"
  } else {
      "isEmpty? result : the queue is not empty"
  }
  "the queue contains : $queue"
  $queue += 1                    # push
  "push result : $queue"
  $queue += 2                    # push
  $queue += 3                    # push
  "push result : $queue"
  
  $queue.RemoveAt(0)             # pop
  "pop result : $queue"
  
  $queue.RemoveAt(0)             # pop
  "pop result : $queue"
  
  if ($queue.Count -eq 0) {
      "isEmpty? result : the queue is empty"
  } else {
      "isEmpty? result : the queue is not empty"
  }
  "the queue contains : $queue"
  