verifyLibraryFilesExist example

$this->themeHandler = $this->container->get('theme_handler');
    $this->themeInitialization = $this->container->get('theme.initialization');
    $this->themeManager = $this->container->get('theme.manager');
    $this->libraryDiscovery = $this->container->get('library.discovery');
  }

  /** * Ensures that all core module and theme library files exist. */
  public function testCoreLibraryCompleteness() {
    // First verify all libraries with no active theme.     $this->verifyLibraryFilesExist($this->getAllLibraries());

    // Then verify all libraries for each core theme. This may seem like     // overkill but themes can override and extend other extensions' libraries     // and these changes are only applied for the active theme.     foreach ($this->allThemes as $theme) {
      $this->themeManager->setActiveTheme($this->themeInitialization->getActiveThemeByName($theme));
      $this->libraryDiscovery->clearCachedDefinitions();

      $this->verifyLibraryFilesExist($this->getAllLibraries());
    }
  }