Return the order that will use the specified unit-of-order for all
async operations, regardless of whether they were invoked from the
same client thread or not.
Return the order that will allow the server to parallelize the
execution of async operations across multiple threads, regardless of
whether they were invoked from the same client thread or not.
Return the order that will ensure that all operations invoked from
the same client thread are executed on the server sequentially, using
the same unit-of-order.