Updated test cases documentation

docs/test_cases/t00041.md

@@ -18,6 +18,9 @@ diagrams:
         - clanguml::t00041::RR
       subclasses:
         - clanguml::t00041::ns1::N
+    exclude:
+      namespaces:
+        - clanguml::t00041::detail
 ```
 ## Source code
 File t00041.cc
@@ -48,9 +51,15 @@ struct E {
 struct F {
 };
 
+namespace detail {
+struct G {
+};
+} // namespace detail
+
 struct RR : public R {
     E *e;
     F *f;
+    detail::G *g;
 };
 
 struct RRR : public RR {