Ensure that optional calls and strictly ordered calls play nicely together

See
- https://github.com/ryanplusplus/mach.js/commit/50a36a35b1f701771ad1d0038cdd28b9b951b3bc
- https://github.com/ryanplusplus/mach.js/commit/ddd19863e89b62bfabb683ad08305eb5fa641197
- https://github.com/ryanplusplus/mach.js/commit/044af0a411d39ffcf8ce97cc35ac0e299bb2bffd
