expose registerhandler method with attribute parameter

Pilz.Net/Api/ApiServer.cs

@@ -190,6 +190,13 @@ public class ApiServer : IApiServer
             return;
         }
 
+        RegisterHandler(handler, attribute, throwOnError);
+    }
+
+    public virtual void RegisterHandler(Delegate handler, ApiMessageHandlerAttribute attribute, bool throwOnError)
+    {
+        var method = handler.Method;
+
         // Resolves parameters
         var url = attribute.Route;
         var useRegEx = false;