protected function loadRecipeFile($filename) {
    if (!file_exists($filename)) {
      throw new FileNotFoundException($filename);
    }
    $recipe = Yaml::parse(
      file_get_contents($filename)
    );
    $configs = [$recipe];
    $processor = new Processor();
    $configuration_tree = new ProjectConfiguration();
    $processed_configuration = $processor->processConfiguration(
      $configuration_tree,
      $configs
    );

    return $processed_configuration;
  }