The MACVLAN network type was added recently. It makes sense that there should be an option for setting a user-defined MAC address.

There should be 2 options:

1. Set the MAC address to a user-defined MAC (e.g. set container name test network test-net mac aa:bb:cc:dd:ee:f0)
2. Hardcode the MAC address from the randomly generated MAC address (e.g. set container name test network test-net mac auto)

The mac auto function would replace mac auto with the actual MAC in the config (e.g. mac aa:bb:cc:dd:ee:f0)