From d0c51a32e04003ae75bd6c7a51f69144fb2a3a7f Mon Sep 17 00:00:00 2001
From: sta <sta.blockhead@gmail.com>
Date: Mon, 21 Oct 2019 21:08:33 +0900
Subject: [PATCH] [Modify] Polish it

---
 websocket-sharp/Net/HttpListenerResponse.cs | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/websocket-sharp/Net/HttpListenerResponse.cs b/websocket-sharp/Net/HttpListenerResponse.cs
index 8787644d..a0752fa5 100644
--- a/websocket-sharp/Net/HttpListenerResponse.cs
+++ b/websocket-sharp/Net/HttpListenerResponse.cs
@@ -170,9 +170,18 @@ namespace WebSocketSharp.Net
       }
 
       set {
-        checkDisposedOrHeadersSent ();
-        if (value < 0)
-          throw new ArgumentOutOfRangeException ("Less than zero.", "value");
+        if (_disposed)
+          throw new ObjectDisposedException (GetType ().ToString ());
+
+        if (_headersSent) {
+          var msg = "The response has already been sent.";
+          throw new InvalidOperationException (msg);
+        }
+
+        if (value < 0) {
+          var msg = "Less than zero.";
+          throw new ArgumentOutOfRangeException (msg, "value");
+        }
 
         _contentLength = value;
       }