public function updateCustomFields(int $conversationId, $customFields): void
    {
        if ($customFields instanceof CustomFieldsCollection) {
            $customFieldsCollection = $customFields;
        } else {
            if ($customFields instanceof Collection) {
                $customFields = $customFields->toArray();
            }

            $customFieldsCollection = new CustomFieldsCollection();
            $customFieldsCollection->setCustomFields($customFields);
        }

        $this->restClient->updateResource(
            $customFieldsCollection,
            sprintf('/v2/conversations/%d/fields', $conversationId)
        );
    }