fn accumulate_exposure<'a>(
net_by_bucket: &mut HashMap<&'a PortfolioMarginOptionKey, f64>,
exposures: &'a [PortfolioMarginOptionExposure],
underlying: &str,
) -> Result<(), MarginError>fn accumulate_exposure<'a>(
net_by_bucket: &mut HashMap<&'a PortfolioMarginOptionKey, f64>,
exposures: &'a [PortfolioMarginOptionExposure],
underlying: &str,
) -> Result<(), MarginError>