But `open()` doesn't use `async` and `await`.

    So, we declare the event handler function with standard `def` instead of `async def`.

### `startup` and `shutdown` together

There's a high chance that the logic for your *startup* and *shutdown* is connected, you might want to start something and then finish it, acquire a resource and then release it, etc.

     * <ul>
     * <li>better simulate a normal development lifecycle where builds are rarely executed
     * back-to-back, as there is typically some work being done between the builds,</li>
     * <li>give file system events a chance to arrive; otherwise we might detect them during
     * the build, and invalidating the VFS,
     * <li>let VFS cleanup (that happens between builds) finish.</li>
     * </ul>
     */

	// timing delay in a different way: So that "one tenth" of a period of CPU
	// spend shows up as a 10% chance of one sample (for an expected value of
	// 0.1 samples), and so that "two and six tenths" periods of CPU spend show
	// up as a 60% chance of 3 samples and a 40% chance of 2 samples (for an
	// expected value of 2.6). Set the initial delay to a value in the unifom

  // but not yet healthy are considered disrupted and can be evicted regardless
  // of whether the criteria in a PDB is met. This means perspective running
  // pods of a disrupted application might not get a chance to become healthy.
  // Healthy pods will be subject to the PDB for eviction.
  //
  // Additional policies may be added in the future.
  // Clients making eviction decisions should disallow eviction of unhealthy pods

<img src="/img/tutorial/body/image03.png">

You also get error checks for incorrect type operations:

<img src="/img/tutorial/body/image04.png">

This is not by chance, the whole framework was built around that design.

And it was thoroughly tested at the design phase, before any implementation, to ensure it would work with all the editors.

	if util.DeploymentComplete(d, &newStatus) || currentCond.Reason == util.TimedOutReason {
		return time.Duration(-1)
	}
	// If there is no sign of progress at this point then there is a high chance that the
	// deployment is stuck. We should resync this deployment at some point in the future[1]
	// and check whether it has timed out. We definitely need this, otherwise we depend on the

means that all running pods (status.phase=\"Running\"), but not yet healthy are considered disrupted and can be evicted regardless of whether the criteria in a PDB is met. This means perspective running pods of a disrupted application might not get a chance to become healthy. Healthy pods will be subject to the PDB for eviction.\n\nAdditional policies may be added in the future. Clients making eviction decisions should disallow eviction of unhealthy pods if they encounter an unrecognized policy in this...

means that all running pods (status.phase=\"Running\"), but not yet healthy are considered disrupted and can be evicted regardless of whether the criteria in a PDB is met. This means perspective running pods of a disrupted application might not get a chance to become healthy. Healthy pods will be subject to the PDB for eviction.\n\nAdditional policies may be added in the future. Clients making eviction decisions should disallow eviction of unhealthy pods if they encounter an unrecognized policy in this...

  // but not yet healthy are considered disrupted and can be evicted regardless
  // of whether the criteria in a PDB is met. This means perspective running
  // pods of a disrupted application might not get a chance to become healthy.
  // Healthy pods will be subject to the PDB for eviction.
  //
  // Additional policies may be added in the future.
  // Clients making eviction decisions should disallow eviction of unhealthy pods

	// 1. It allows a watch-fed cache time to observe a namespace creation event
	// 2. It allows time for a namespace creation to distribute to members of a storage cluster,
	//    so the live lookup has a better chance of succeeding even if it isn't performed against the leader.
	missingNamespaceWait = 50 * time.Millisecond
)

// Register registers a plugin
func Register(plugins *admission.Plugins) {