//! In-process test broker, behind the `testing` feature.
//!
//! [`KafkaTestBroker`] implements the core `TestableBroker` contract over an in-memory router
//! so application handlers wired against Kafka descriptors can be exercised without a cluster:
//! messages fan out synchronously to subscribers matched by exact topic name.
//!
//! Scope: topic-name routing, settlement, headers, and the partition-key header. Consumer
//! groups, partitions, committed offsets, start offsets, and rebalancing are transport
//! behavior; exercise them against a real cluster (see the crate's integration tests and
//! `KAFKA_TEST_URL`).
pub use KafkaTestBroker;
pub use KafkaTestPublisher;
pub use ;