-fun cpp_call_context: CppCallContext do return once new CppCallContext
-fun to_cpp_call_context: ToCppCallContext do return once new ToCppCallContext
-fun from_cpp_call_context: FromCppCallContext do return once new FromCppCallContext
+private fun cpp_call_context: CppCallContext do return once new CppCallContext
+private fun to_cpp_call_context: ToCppCallContext do return once new ToCppCallContext
+private fun from_cpp_call_context: FromCppCallContext do return once new FromCppCallContext