//! Internal helpers backing the higher-level pullers.
//!
//! * [`fast_puller`] (feature `fast-puller`): the `FastDownPuller`
//! type and its `FastDownPullerOptions`, plus `build_client`
//! which constructs a correctly-configured `SmartRedirectClient`.
//! * [`getifaddrs`] (feature `getifaddrs`): enumerates the machine's non-virtual
//! local IP addresses for multi-interface download setups.