code: public function collect(&$test, $path)
      {
          $path = $this->removeTrailingSlash($path);
          if ($handle = opendir($path)) {
              while (($entry = readdir($handle)) !== false) {
                  if ($this->isHidden($entry)) {
                      continue;
                  }
                  $this->handle($test, $path . DIRECTORY_SEPARATOR . $entry);
              }
              closedir($handle);
          }
      }
docs: Scans the directory and adds what it can.
  
  @param object $test Group test with {@link GroupTest::addFile)} method.
  @param string $path Directory to scan.
  
  @see _attemptToAdd()