Added cyclic dependency include diagram test case

tests/t40002/src/lib1/lib1.cc

@@ -0,0 +1,11 @@
+#include "../../include/lib1/lib1.h"
+
+namespace clanguml::t40002::lib1 {
+
+int foo0() { return 0; }
+
+int foo1() { return 1; }
+
+int foo() { return foo1(); }
+
+}