Function candidate_balance_epsilon 

fn candidate_balance_epsilon(
    candidate_assets: &[AssetRef],
    region_id: &RegionID,
    commodity_id: &CommodityID,
    ts_selection: &TimeSliceSelection,
    epsilon: Flow,
) -> Flow

Calculate the epsilon to add to the lower bound of a commodity balance constraint, to force some dispatch by candidate assets so they receive a nonzero shadow price.

Returns epsilon if the total maximum output from candidate assets in region_id for commodity_id in ts_selection exceeds epsilon, otherwise returns zero (to avoid making the balance constraint infeasible).