code: func priorityClassPermittedInNamespace(priorityClassName string, namespace string) bool {
  	// Only allow system priorities in the system namespace. This is to prevent abuse or incorrect
  	// usage of these priorities. Pods created at these priorities could preempt system critical
  	// components.
  	for _, spc := range scheduling.SystemPriorityClasses() {
  		if spc.Name == priorityClassName && namespace != metav1.NamespaceSystem {
  			return false
  		}
  	}
  	return true
  }
docs: // priorityClassPermittedInNamespace returns true if we allow the given priority class name in the
  // given namespace. It currently checks that system priorities are created only in the system namespace.