The code only changed from the previous example in only one place: the values placed in the PROVIDER_URL key of the environment Hashtable object.
相對於前一個示例,此代碼僅在一個地方進行了更改:放在環境Hashtable對象的provider_url鍵中的值。
例如,假定往Hashtable中添加元素並從中檢索元素。
For example, suppose we are adding and retrieving elements to and from a Hashtable.