code: function handleResults(context, results) {
  
    if (checkedPages.indexOf(results.url) === -1) {
  
      checkedPages.push(results.url);
  
      results.violations.forEach(violation => {
        
        let specName = `${violation.help} (${results.url})`;
        let message = '\n' + buildMessage(violation);
  
        context.addFailure(message, {specName});
  
      });
  
    }
  
  }
docs: Processes the axe-core results by reporting recognized violations
  to Protractor and printing them out.
  @param {!protractor.ProtractorPlugin} context
  @param {!axe.AxeResults} results