code: func (m *AdmissionMetrics) ObserveAdmissionController(elapsed time.Duration, rejected bool, attr admission.Attributes, stepType string, extraLabels ...string) {
  	m.controller.observe(elapsed, append(extraLabels, stepType, string(attr.GetOperation()), strconv.FormatBool(rejected))...)
  }
docs: // ObserveAdmissionController records admission related metrics for a built-in admission controller, identified by it's plugin handler name.