final Map<String, Object> keys = mapKey(uriInfo.getTargetKeyPredicates());
final Object targetData = dataSource.readRelatedData(entitySet, sourceData, targetEntitySet, keys);
if (!appliesFilter(targetData, uriInfo.getFilter())) {
throw new ODataNotFoundException(ODataNotFoundException.ENTITY);
}
dataSource.deleteRelation(entitySet, sourceData, targetEntitySet, keys);
final Map<String, Object> newKeys = parseLink(targetEntitySet, content, requestContentType);