//! Internal `TopologyImpl` trait. See DESIGN_V2.md ยง5.
use crateResult;
use crateTopic;
// Methods are anchored by the InMemory port's `_anchor_*` helpers in
// `backend::mod` under the `inmemory` feature. Under
// `--no-default-features` no backend is compiled, so the trait method
// genuinely has no call site; `dead_code` is expected there and the
// per-trait allow avoids polluting the default build with warnings
// until Phase 5+ adds the generic wrappers.
pub