private function getImageFieldIdentifier($contentId, $language, $related = false)
    {
        $content = $this->contentService->loadContent($contentId);
        $contentType = $this->contentTypeService->loadContentType($content->contentInfo->contentTypeId);

        $fieldDefinitions = $this->getFieldDefinitionList();
        $fieldNames = array_flip($fieldDefinitions);

        if (in_array('ezimage', $fieldDefinitions)) {
            return $fieldNames['ezimage'];
        } elseif (in_array('ezobjectrelation', $fieldDefinitions) && !$related) {
            $field = $content->getFieldValue($fieldNames['ezobjectrelation'], $language);

            if (!empty($field->destinationContentId)) {
                return $this->getImageFieldIdentifier($field->destinationContentId, $language, true);
            }
        } else {
            return $this->getConfiguredFieldIdentifier('image', $contentType);
        }
    }