/**
  * Gets the range of the property.
  *
  * @param AttributeMetadataInterface $attributeMetadata
  *
  * @return string|null
  */
 private function getRange(AttributeMetadataInterface $attributeMetadata)
 {
     $type = $attributeMetadata->getType();
     if (!$type) {
         return;
     }
     if ($type->isCollection() && ($collectionType = $type->getCollectionType())) {
         $type = $collectionType;
     }
     switch ($type->getType()) {
         case 'string':
             return 'xmls:string';
         case 'int':
             return 'xmls:integer';
         case 'float':
             return 'xmls:double';
         case 'bool':
             return 'xmls:boolean';
         case 'object':
             $class = $type->getClass();
             if ($class) {
                 if ('DateTime' === $class) {
                     return 'xmls:dateTime';
                 }
                 if ($resource = $this->resourceCollection->getResourceForEntity($type->getClass())) {
                     return sprintf('#%s', $resource->getShortName());
                 }
             }
             break;
     }
 }