InvocationMessage
BMessage* InvocationMessage() const;
BMessage* InvocationMessage() const;
BMessage* InvocationMessage() const;
if (status >= B_OK && InvocationMessage() != NULL)
status = data->AddMessage("_msg", InvocationMessage());
if (status >= B_OK && InvocationMessage() != NULL)
status = archive->AddMessage("_msg", InvocationMessage());
if (status == B_OK && InvocationMessage())
status = archive->AddMessage("_invokeMsg", InvocationMessage());