{ lib, options, ... }:
# Some modules may be distributed separately and need to adapt to other modules
# that are distributed and versioned separately.
{
# Always defined, but the value depends on the presence of an option.
config.set =
value = if options ? set.enable then 360 else 7;
}
# Only define if possible.
// lib.optionalAttrs (options ? set.enable) {
enable = true;
};