copilot comments

Author: Sophia Tevosyan

client/src/main/java/com/microsoft/durabletask/DurableTaskGrpcClientFactory.java

@@ -9,6 +9,10 @@
 public final class DurableTaskGrpcClientFactory {
     private static final ConcurrentMap<Integer, DurableTaskGrpcClient> portToClientMap = new ConcurrentHashMap<>();
 
+    // Private to prevent instantiation and enforce a singleton pattern
+    private DurableTaskGrpcClientFactory() {
+    }
+
     public static DurableTaskClient getClient(int port, String defaultVersion) {
         return portToClientMap.computeIfAbsent(port, DurableTaskGrpcClient::new);
     }