validates:policy_id,uniqueness: {scope: [:oncall_schedule_id,:status,:elapsed_time_seconds],message: _('Must have a unique policy, status, and elapsed time')}
it{is_expected.tovalidate_uniqueness_of(:policy_id).scoped_to([:oncall_schedule_id,:status,:elapsed_time_seconds]).with_message('Must have a unique policy, status, and elapsed time')}