public function getRecentEntities()
 {
     REST::requireRequestMethod('GET');
     $db = new MySQL();
     $entitiesNode = new XMLNode('entities');
     foreach (Model::getRecentEntities() as $entity) {
         $entityNode = new XMLNode('entity');
         $entityNode->setAttribute('identifier', $entity['IDENTIFIER']);
         $entityNode->setAttribute('friendlyname', $entity['FRIENDLYNAME']);
         $entityNode->setAttribute('lat', $entity['LATITUDE']);
         $entityNode->setAttribute('lon', $entity['LONGITUDE']);
         $entityNode->setAttribute('date', strtotime($entity['DATETIME']));
         $entitiesNode->addNode($entityNode);
     }
     $xmlDoc = new XMLDocument();
     $xmlDoc->setRootNode($entitiesNode);
     REST::sendResponse(200, $xmlDoc, 'application/xml');
 }