From f642de6c7636ffa9fadf9e944dae44232f274c26 Mon Sep 17 00:00:00 2001
From: Brady Gaster <41929050+bradygaster@users.noreply.github.com>
Date: Mon, 3 Apr 2023 08:51:49 -0700
Subject: [PATCH] ObserverManager: Guard against `null` in constructor (#8358)

* check logger for null

* Update src/Orleans.Core/Utils/ObserverManager.cs

* Update src/Orleans.Core/Utils/ObserverManager.cs

---------

Co-authored-by: Setup <setup@example.com>
Co-authored-by: Reuben Bond <203839+ReubenBond@users.noreply.github.com>
---
 src/Orleans.Core/Utils/ObserverManager.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Orleans.Core/Utils/ObserverManager.cs b/src/Orleans.Core/Utils/ObserverManager.cs
index efd737b85f..9c24b2f027 100644
--- a/src/Orleans.Core/Utils/ObserverManager.cs
+++ b/src/Orleans.Core/Utils/ObserverManager.cs
@@ -59,7 +59,7 @@ public class ObserverManager<TIdentity, TObserver> : IEnumerable<TObserver>
         public ObserverManager(TimeSpan expiration, ILogger log)
         {
             ExpirationDuration = expiration;
-            _log = log;
+            _log = log ?? throw new ArgumentNullException(nameof(log));
             GetDateTime = () => DateTime.UtcNow;
         }