Interface IOrder

If IOrder.first === "before" && IOrder.last === "unique", each stage will run serially following the order:

1. before
2. schema
3. unique

However, all tests within each stage will be run in parallel.

If only IOrder.first is defined, but not IOrder.last, the other two stages will run in parallel after the first has completed. As an example, if IOrder.first === "before" and IOrder.last is undefined, then schema and unique checks will run in parallel after before checks have completed.

The same also applies in reverse, when only IOrder.last is defined. As an example, if IOrder.last === "schema" and IOrder.first is undefined, both before and unique tasks would run in parallel first while schema tasks would only be run after they have completed.

If both IOrder.first and IOrder.last are undefined all tests will be run in parallel.