code: function setupRegistryForEachAddon(registry, parent) {
    parent.initializeAddons();
    let addons = parent.addons || (parent.project && parent.project.addons);
  
    if (!addons) {
      return;
    }
  
    addons.forEach(addon => {
      if (addon.setupPreprocessorRegistry) {
        addon.setupPreprocessorRegistry('parent', registry);
      }
    });
  }
docs: Invokes the `setupRegistryForEachAddon('parent', registry)` hook for each of the parent objects addons.
  
  @private
  @method setupRegistryForEachAddon
  @param {Registry} registry the registry being setup
  @param {Addon|EmberApp} parent the parent object of the registry being setup. Will be an addon for nested
  addons, or the `EmberApp` for addons in the project directly.