code: @DataProvider(parallel = true)
      public static Iterator<String[]> availableUniqueBrowsers(ITestContext context, Constructor<?> testConstructor)
              throws Exception {
  
          Map<String, String> map = new HashMap<String, String>();
          List<String> browsers = gridBrowsers(map);
  
          HashSet<String> hs = new HashSet<String>();
          hs.addAll(browsers);
          browsers.clear();
          browsers.addAll(hs);
  
          return buildIterator(browsers);
      }
docs: Get unique browsers available in a selenium grid.
  
  @param context context
  @param testConstructor testConstructor
  @return an iterator
  @throws Exception exception