Potential Enhancements

Here are a few enhancements that I see being useful.
- Add functionality for a global start/end time in the addExposures function call. This is easier than filtering the final dataset, which could get massive, especially if you're talking about monthly exposures on hundreds of thousands of old policies with older issue dates. Changing the start_int and end_int in the input dataset doesn't seem to be an option as it would result in incorrect durations.
- Add functionality to carry policy level attributes through the addExposures function. Today if you call addExposures(records) the 'gender' variable is dropped. I know it's possible right now to run addExposures and then left join the attributes from the original dataset back on, but this is an extra step that we can eliminate from users work flows.