//! Execution backend catalog.
//!
//! A backend describes *how* a whole pipeline run is executed.
//! The first real backends are expected to be:
//!
//! - resident local execution
//! - resident remote worker execution
//!
//! Future backends include isolated job-oriented execution such as Docker, Kubernetes,
//! or Spark-oriented submission backends.
pub use ;
pub use ResidentLocalBackend;
pub use ResidentWorkerBackend;