message: Moar comments.
diff: @@ -5,10 +5,14 @@ use itertools::Itertools;
  use std::collections::HashMap;
  use tracing::debug;
  +/// Metrics for event queue sizes.
  #[derive(Debug)]
  pub(super) struct EventQueueMetrics {
  + /// Per queue kind gauges that measure number of event in the queue.
  event_queue_gauges: HashMap<QueueKind, IntGauge>,
  + /// Total events count.
  event_total: IntGauge,
  + /// Instance of registry to unregister from when being dropped.
  registry: Registry,
  }
  