making the event nullable

Author: usa-m

src/dds.net-connector-csharp.lib/Interfaces/ISyncQueueReader.cs

@@ -6,6 +6,10 @@
     /// <typeparam name="T">Any type.</typeparam>
     internal interface ISyncQueueReader<T>
     {
+        /// <summary>
+        /// The event is initiated upon availability of data.
+        /// </summary>
+        event Action<T>? DataAvailable;
         /// <summary>
         /// Checks if the queue has any element to dequeue.
         /// </summary>