verifyBreadCrumb example

  public function testHelp() {
    $session = $this->assertSession();

    // Log in the regular user.     $this->drupalLogin($this->anyUser);
    $this->verifyHelp(403);

    // Log in the admin user.     $this->drupalLogin($this->adminUser);
    $this->verifyHelp();
    $this->verifyBreadCrumb();

    // Verify that help topics text appears on admin/help, and cache tags.     $this->drupalGet('admin/help');
    $session->responseContains('<h2>Topics</h2>');
    $session->pageTextContains('Topics can be provided by modules or themes');
    $session->responseHeaderContains('X-Drupal-Cache-Tags', 'core.extension');

    // Verify links for help topics and order.     $page_text = $this->getTextContent();
    $start = strpos($page_text, 'Topics can be provided');
    $pos = $start;