fn group_allocations<'a>(
table_id: TableId,
regions: &'a [(RegionNumber, String)],
affinity: &'a AllocationAffinity,
) -> Vec<AllocationGroup<'a>>fn group_allocations<'a>(
table_id: TableId,
regions: &'a [(RegionNumber, String)],
affinity: &'a AllocationAffinity,
) -> Vec<AllocationGroup<'a>>