frame.writeByte(255) // Heaviest weight, zero-indexed.
    frame.writeAll(headerBytes)
    reader.nextFrame(
      requireSettings = false,
      object : BaseTestHandler() {
        override fun priority(
          streamId: Int,
          streamDependency: Int,
          weight: Int,
          exclusive: Boolean,
        ) {
          assertThat(streamDependency).isEqualTo(0)

## Changelog since v1.18.18

## Changes by Kind

### API Change

- We have added a new Priority & Fairness rule that exempts all probes (/readyz, /healthz, /livez) to prevent 

- Azure: Skip "instance not found" error for LB backend address pools ([#111428](https://github.com/kubernetes/kubernetes/pull/111428), [@lzhecheng](https://github.com/lzhecheng)) [SIG Cloud Provider]
- Fix list cost estimation in Priority and Fairness for list requests with metadata.name specified. ([#112557](https://github.com/kubernetes/kubernetes/pull/112557), [@marseel](https://github.com/marseel)) [SIG API Machinery]

- Update kube-apiserver's priority & fairness work estimator such that 'max seats' is MIN(0.15 x nominalCL, nominalCL / handSize)
  

- In the API Priority and Fairness feature, priority levels that are exempt from limitation can now be given a nominal and a lendable concurrency and their dispatching borrows from the concurrency limits of the other priority levels.  For details see https://github.com/kubernetes/enhancements/tree/master/keps/sig-api-machinery/1040-priority-and-fairness#dispatching . ([#118782](https://github.com/kubernetes/kubernetes/pull/118782),...

* Priority admission controller picks a global default with the lowest priority value if more than one such default PriorityClass exists. ([#59991](https://github.com/kubernetes/kubernetes/pull/59991), [@bsalamat](https://github.com/bsalamat))

- Update default API priority-and-fairness config to avoid endpoint/configmaps operations from controller-manager to all match leader-election priority level. ([#106725](https://github.com/kubernetes/kubernetes/pull/106725), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery]

### Feature

- A new Priority and Fairness metric 'apiserver_flowcontrol_work_estimate_seats_samples' has been 

  * New SchedulerExtender enables users to implement custom
out-of-(the-scheduler)-process scheduling predicates and priority functions,
for example to schedule pods based on resources that are not directly managed

* Kubelet won't evict a static pod with priority `system-node-critical` upon resource pressure. ([#74222](https://github.com/kubernetes/kubernetes/pull/74222), [@Huang-Wei](https://github.com/Huang-Wei))

- Update kube-apiserver's priority & fairness work estimator such that 'max seats' is MIN(0.15 x nominalCL, nominalCL / handSize)