+/**
+ * A scorer that is accessed under a lock.
+ *
+ * Needed so that calls to [`Score::channel_penalty_msat`] in [`find_route`] can be made while
+ * having shared ownership of a scorer but without requiring internal locking in [`Score`]
+ * implementations. Internal locking would be detrimental to route finding performance and could
+ * result in [`Score::channel_penalty_msat`] returning a different value for the same channel.
+ *
+ * [`find_route`]: crate::routing::router::find_route
+ */