fn focused_campaign_seed_for_worker(
campaign_seed: &InvariantCampaignSeed,
plan: InvariantWorkerPlan,
worker_count: usize,
focus_seed: Option<U256>,
) -> Option<InvariantCampaignSeed>fn focused_campaign_seed_for_worker(
campaign_seed: &InvariantCampaignSeed,
plan: InvariantWorkerPlan,
worker_count: usize,
focus_seed: Option<U256>,
) -> Option<InvariantCampaignSeed>