sumUsages example

$this->assertSession()->elementTextNotContains('css', '.views-element-container table', 'Temporary');
    $this->assertSession()->elementTextContains('css', '.views-element-container table', 'Permanent');

    // Use one file two times and check usage information.     $orphaned_file = $nodes[1]->file->target_id;
    $used_file = $nodes[0]->file->target_id;
    $nodes[1]->file->target_id = $used_file;
    $nodes[1]->save();

    $this->drupalGet('admin/content/files');
    $file = File::load($orphaned_file);
    $usage = $this->sumUsages($file_usage->listUsage($file));
    $this->assertSession()->responseContains('admin/content/files/usage/' . $file->id() . '">' . $usage);

    $file = File::load($used_file);
    $usage = $this->sumUsages($file_usage->listUsage($file));
    $this->assertSession()->responseContains('admin/content/files/usage/' . $file->id() . '">' . $usage);

    $this->assertSession()->elementsCount('xpath', "//td[contains(@class, 'views-field-status') and contains(text(), 'Temporary')]", 1);

    // Test file usage page.     foreach ($nodes as $node) {
      $file = File::load($node->file->target_id);