interface VersionNegotiatorInterface

interface VersionNegotiatorInterface {
    
    /**
     * Gets the identified revision.
     *
     * The JSON:API module exposes revisions in terms of RFC5829. As such, the
     * public API always refers to "versions" and "working copies" instead of
     * "revisions". There are multiple ways to request a specific revision. For
     * example, one might like to load a particular revision by its ID. On the
     * other hand, it may be useful if an HTTP consumer is able to always request
     * the "latest version" regardless of its ID. It is possible to imagine other
     * scenarios as well, like fetching a revision based on a date or time.
     *
     * Each version negotiator provides one of these strategies and is able to map
     * a version argument to an existing revision.
     *
     * @param \Drupal\Core\Entity\EntityInterface $entity
     *   The entity for which a revision should be resolved.
     * @param string $version_argument
     *   A value used to derive a revision for the given entity.
     *
     * @return \Drupal\Core\Entity\EntityInterface
     *   The identified entity revision.
     *
     * @throws \Drupal\jsonapi\Revisions\VersionNotFoundException
     *   When the revision does not exist.
     * @throws \Drupal\jsonapi\Revisions\InvalidVersionIdentifierException
     *   When the revision ID is invalid.
     */
    public function getRevision(EntityInterface $entity, $version_argument);

}