//! Visitors that implement the XVA simulation pipeline.
//!
//! * [`PreprocessorExecutor`](preprocessorexecutor::PreprocessorExecutor) -- collects market-data requests from claims.
//! * [`MarketModel`](marketmodel::MarketModel) -- trait for Monte Carlo path generation.
//! * [`ExposureEvaluator`](exposureevaluator::ExposureEvaluator) -- computes NPV cubes,
//! exposure profiles (EPE/ENE/EE), and optionally XVA values with sensitivities.
/// Claim preprocessing into simulation requests.
/// Historical-fixing preprocessing.