diff --git a/src/Entities/WorkItem.cs b/src/Entities/WorkItem.cs
index 03db258..7a705cc 100644
--- a/src/Entities/WorkItem.cs
+++ b/src/Entities/WorkItem.cs
@@ -95,7 +95,7 @@ public void AddTimeByState(TimeByState timeByState)
 
         public void AddTimesByState(IEnumerable<TimeByState> timesByState)
         {
-            if (timesByState is not null && !timesByState.Any())
+            if (timesByState is null || timesByState?.Any() == false)
                 return;
 
             foreach (var timeByState in timesByState)
diff --git a/src/Extensions/HelperExtenions.cs b/src/Extensions/HelperExtenions.cs
index f4a5859..a233420 100644
--- a/src/Extensions/HelperExtenions.cs
+++ b/src/Extensions/HelperExtenions.cs
@@ -22,10 +22,10 @@ public static string ExtractEmail(this string user)
             if (user is null)
                 return user;
 
-            if (!user.Contains(" <") && !user.TrimEnd().Contains(">"))
+            if (!user.Contains(" <") && !user.TrimEnd().Contains('>'))
                 return user;
 
-            return user.Split("<").LastOrDefault().Split(">").FirstOrDefault();
+            return user.Split('<').LastOrDefault()?.Split('>')?.FirstOrDefault();
         }
 
         public static string ToTextTime(this TimeSpan timeSpan)