protected function mergeFieldMap(Content $content, array $fieldMap, array $languageCodes)
{
if (empty($fieldMap)) {
return $content->fields;
}
$mergedFieldMap = array();
foreach ($content->fields as $fieldIdentifier => $fieldLanguageMap) {
foreach ($languageCodes as $languageCode) {
$mergedFieldMap[$fieldIdentifier][$languageCode] = isset($fieldMap[$fieldIdentifier][$languageCode]) ? $fieldMap[$fieldIdentifier][$languageCode] : $fieldLanguageMap[$languageCode];
}
}
return $mergedFieldMap;
}