getPatchDocument example

    if ($this->entity instanceof ConfigEntityInterface) {
      $this->markTestSkipped('PATCHing config entities is not yet supported.');
    }

    $prior_revision_id = (int) $this->entityLoadUnchanged($this->entity->id())->getRevisionId();

    // Patch testing requires that another entity of the same type exists.     $this->anotherEntity = $this->createAnotherEntity('dupe');

    // Try with all of the following request bodies.     $unparseable_request_body = '!{>}<';
    $parseable_valid_request_body = Json::encode($this->getPatchDocument());
    if ($this->entity->getEntityType()->hasKey('label')) {
      $parseable_invalid_request_body = Json::encode($this->makeNormalizationInvalid($this->getPatchDocument(), 'label'));
    }
    $parseable_invalid_request_body_2 = Json::encode(NestedArray::mergeDeep(['data' => ['attributes' => ['field_rest_test' => $this->randomString()]]], $this->getPatchDocument()));
    // The 'field_rest_test' field does not allow 'view' access, so does not end     // up in the JSON:API document. Even when we explicitly add it to the JSON     // API document that we send in a PATCH request, it is considered invalid.     $parseable_invalid_request_body_3 = Json::encode(NestedArray::mergeDeep(['data' => ['attributes' => ['field_rest_test' => $this->entity->get('field_rest_test')->getValue()]]], $this->getPatchDocument()));
    $parseable_invalid_request_body_4 = Json::encode(NestedArray::mergeDeep(['data' => ['attributes' => ['field_nonexistent' => $this->randomString()]]], $this->getPatchDocument()));
    // It is invalid to PATCH a relationship field under the attributes member.     if ($this->entity instanceof FieldableEntityInterface && $this->entity->hasField('field_jsonapi_test_entity_ref')) {