JackLiang1272

Add merge option

1

# Overview Add merge option "first", "last", "nearest", and "count" on top of "forward". ## Description of changes Add merge option "first", "last", "nearest", and "count" on top of "forward"....

## Is your feature request related to a problem? Please describe prediction_path and event_path are consider required even when predictions_frame is populated. Because load_yml will populate the field with None...