Wherever Application::log is called with some pvl group (here called `pvlgroup`), in the app func replace with:
```C++
if (log){
log->addGroup(pvlgroup);
}
```
## Creating a more complex callable function
The basic interface that we've created so far is simply a mirror of the application command line interface. In order to further improve the testability of the application, we should break the application down into functional components.
