Function can_be_active 

fn can_be_active(
    process: &Process,
    target: &(RegionID, u32),
    time_slice_selection: &TimeSliceSelection,
) -> bool

Checks if a process can be active for a particular timeslice in a given year and region

It considers all commission years that can lead to a running process in the target region and year, accounting for the process lifetime, and then checks if, for any of those, the process is active in the required timeslice. In other words, this checks if there is the possibility of having an active process, although there is no guarantee of that happening since it depends on the investment.