# Microsoft.Extensions.FileSystemGlobbing.Internal.PatternContexts

``` diff
 namespace Microsoft.Extensions.FileSystemGlobbing.Internal.PatternContexts {
     public abstract class PatternContext<TFrame> : IPatternContext {
-        protected TFrame Frame;
+        protected TFrame? Frame;
-        protected void PushDataFrame(TFrame frame);
+        protected void PushDataFrame(TFrame? frame);
     }
     public abstract class PatternContextLinear : PatternContext<PatternContextLinear.FrameData> {
         public struct FrameData {
-            public string Stem { get; }
+            public string? Stem { get; }
         }
     }
     public abstract class PatternContextRagged : PatternContext<PatternContextRagged.FrameData> {
         public struct FrameData {
-            public string Stem { get; }
+            public string? Stem { get; }
         }
     }
 }
```

