/**
  * {@inheritdoc}
  */
 public function getRootInstallerDescriptor($name)
 {
     $this->assertInstallersLoaded();
     if (!isset($this->rootInstallerDescriptors[$name])) {
         throw NoSuchInstallerException::forInstallerNameAndPackageName($name, $this->rootPackage->getName());
     }
     return $this->rootInstallerDescriptors[$name];
 }