HttpSessionClientOnWebSocketClosing 方法
            调用前触发WebSocket关闭时的插件
            
命名空间: TouchSocket.Http程序集: TouchSocket.Http (在 TouchSocket.Http.dll 中) 版本:4.0.0-beta.143+5fcca7a4e70968794985dc3793adc50531308be6
protected virtual Task OnWebSocketClosing(
	IWebSocket webSocket,
	ClosingEventArgs e
)
Protected Overridable Function OnWebSocketClosing ( 
	webSocket As IWebSocket,
	e As ClosingEventArgs
) As Task
abstract OnWebSocketClosing : 
        webSocket : IWebSocket * 
        e : ClosingEventArgs -> Task 
override OnWebSocketClosing : 
        webSocket : IWebSocket * 
        e : ClosingEventArgs -> Task 
- webSocket  IWebSocket
 - 当前的WebSocket实例
 - e  ClosingEventArgs
 - 关闭事件的参数
 
Task异步任务