/**
  * Testing the highlight() method.
  *
  * @since 2.0.1
  * @dataProvider getHighlightProviders
  */
 public function testHighlight($provider)
 {
     $highlighter = HighlightProviderFactory::getInstance($provider);
     $code = '<?= $value ?>';
     $highlighted = $highlighter->highlight($code, 'php');
     $this->assertNotEmpty($highlighted, 'Testing the highlight() method');
     $this->assertTrue(Validator::isHTML($highlighted), 'Testing the highlight() method');
 }