const namespace … const subsystem … var jwtAuthenticatorLatencyMetric … var registerMetrics … func RegisterMetrics() { … } func recordAuthenticationLatency(result, jwtIssuerHash string, duration time.Duration) { … } func getHash(data string) string { … } func newInstrumentedAuthenticator(jwtIssuer string, delegate AuthenticatorTokenWithHealthCheck) AuthenticatorTokenWithHealthCheck { … } func newInstrumentedAuthenticatorWithClock(jwtIssuer string, delegate AuthenticatorTokenWithHealthCheck, clock clock.PassiveClock) *instrumentedAuthenticator { … } type instrumentedAuthenticator … func (a *instrumentedAuthenticator) AuthenticateToken(ctx context.Context, token string) (*authenticator.Response, bool, error) { … } func (a *instrumentedAuthenticator) HealthCheck() error { … }