Este ejemplo no implementa el callback en sí (eso podría ser solo una línea de código), solo la parte de documentación.

/// tip | Consejo

El callback real es solo un request HTTP.

- Added support for cloud provider integrations to supply optional, per-Node custom labels that will be
  applied to Nodes by the node controller.
  Extra labels will only be applied where the cloud provider integration implements this. ([#123223](https://github.com/kubernetes/kubernetes/pull/123223), [@mmerkes](https://github.com/mmerkes)) [SIG Cloud Provider]

httpx.post(callback_url, json={"description": "Invoice paid", "paid": True})
```

Mas possivelmente a parte mais importante do callback é garantir que o usuário da sua API (o desenvolvedor externo) implemente a *API externa* corretamente, de acordo com os dados que *sua API* vai enviar no corpo da solicitação do callback, etc.

  * [alpha] CRI now supports specifying the GID of the container at both LinuxSandboxSecurityContext and LinuxContainerSecurityContext in addition to specifying the UID. Support is implemented for dockershim. [@krmayankk]

	}

	// Sub policy not set. Evaluate only the parent policies.
	return (isOwnerDerived || combinedPolicy.IsAllowed(parentArgs))
}

// IsAllowedSTS is meant for STS based temporary credentials,
// which implements claims validation and verification other than
// applying policies.
func (sys *IAMSys) IsAllowedSTS(args policy.Args, parentUser string) bool {
	// 1. Determine mapped policies

- vSphereVolume implements Raw Block Volume Support  ([#68761](https://github.com/kubernetes/kubernetes/pull/68761), [@fanzhangio](https://github.com/fanzhangio))

- `kube-scheduler` implements scheduling hints for the `NodeAffinity` plugin.
  The scheduling hints allow the scheduler to only retry scheduling a `Pod`

 * once created, the abstract pathname represented by an SmbFile object
 * will never change.
 *
 * @see java.io.File
 */

public class SmbFile extends URLConnection implements SmbResource, SmbConstants {
    /**
     * Mask for attributes that can be retrieved from the server
     */
    protected static final int ATTR_GET_MASK = 0x7FFF;
    /**

- [ ] Define lease state constants (SMB2_LEASE_READ, SMB2_LEASE_HANDLE, SMB2_LEASE_WRITE)
- [ ] Implement lease key generation and management
- [ ] Add lease context to Create request/response
- [ ] Implement lease break notification handling
- [ ] Modify SmbFile to support lease-based caching
- [ ] Add lease upgrade/downgrade logic
- [ ] Implement lease epoch tracking for v2 leases

#### 1.3 Integration Points

 * additional documentation, including <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#notes-for-implementors">notes for
 * implementors</a>
 *
 * @author Joshua O'Madadhain
 * @author Jens Nyman
 * @param <N> Node parameter type
 * @since 23.0
 */
@Beta
@DoNotMock("Implement with a lambda, or use GraphBuilder to build a Graph with the desired edges")
public interface SuccessorsFunction<N> {

  /**