/**
  * {@inheritdoc}
  */
 public function findRootAssetMappings(Expression $expr)
 {
     $bindings = $this->discoveryManager->findRootBindings($this->exprBuilder->buildExpression($expr));
     $mappings = array();
     foreach ($bindings as $binding) {
         $mappings[] = $this->bindingToMapping($binding);
     }
     return $mappings;
 }