Adding tests for method calls in foreign namespaces
diff --git a/tests/ffi/tests.h b/tests/ffi/tests.h
index 40bc802..3835660 100644
--- a/tests/ffi/tests.h
+++ b/tests/ffi/tests.h
@@ -182,4 +182,16 @@
   void ns_c_take_trivial(::tests::D d);
   ::tests::D ns_c_return_trivial();
   void ns_c_take_ns_shared(::A::AShared shared);
-} // namespace other
\ No newline at end of file
+} // namespace other
+
+namespace I {
+  class I {
+  private:
+    uint32_t a;
+  public:
+    I() : a(1000) {}
+    uint32_t get() const;
+  };
+
+  std::unique_ptr<I> ns_c_return_unique_ptr_ns();
+} // namespace I