fix:属性污染

@@ -18,13 +18,19 @@ class Client extends ServiceManager
 
     private string $requestOption = '';
 
-    private bool $withSession = false;
+    private bool $withSession;
 
-    public function __construct(Application $app)
+    public function __construct(
+        Application $app, $requestOption = '', $withSession = false
+    )
     {
         parent::__construct($app);
 
         $this->listen();
+
+        $this->requestOption = $requestOption;
+
+        $this->withSession = $withSession;
     }
 
     protected function listen()
@@ -37,30 +43,38 @@ class Client extends ServiceManager
 
     public function asForm(): Client
     {
-        $this->requestOption = RequestOptions::FORM_PARAMS;
-
-        return $this;
+        return new Client(
+            $this->app,
+            RequestOptions::FORM_PARAMS,
+            $this->withSession
+        );
     }
 
     public function asJson(): Client
     {
-        $this->requestOption = RequestOptions::JSON;
-
-        return $this;
+        return new Client(
+            $this->app,
+            RequestOptions::JSON,
+            $this->withSession
+        );
     }
 
     public function asMultipart(): Client
     {
-        $this->requestOption = RequestOptions::MULTIPART;
-
-        return $this;
+        return new Client(
+            $this->app,
+            RequestOptions::MULTIPART,
+            $this->withSession
+        );
     }
 
     public function withSession(): Client
     {
-        $this->withSession = true;
-
-        return $this;
+        return new Client(
+            $this->app,
+            $this->requestOption,
+            true
+        );
     }
 
     public function refresh()