// Package metrics as a subpackage of package matcher, contains many assertion patterns
// as well — just with more focus on metrics and status of TiDBCluster, especially
// those related to Prometheus.
//
// As these assertions mainly focus on Prometheus metrics data reported by the cluster,
// we specially call these assertions "checker". They all use a shared mechanism
// provided by endless: metrics.checker.
//
// Use these checkers with matcher.TolerateByDuration could endure those (probably
// false-positive) anomalies reported by Prometheus.
package metrics