private boolean isFileSystemLocation(Location location) {
    try {
      if (!(location instanceof StandardLocation)) {
        return false;
      }
      final StandardLocation loc = StandardLocation.valueOf(location.getName());
      if (loc == StandardLocation.PLATFORM_CLASS_PATH) {
        return myJavacBefore9;
      }
      return ourFSLocations.contains(loc);
    }
    catch (IllegalArgumentException ignored) {
      return false; // assume 'unknown' location is a non-FS location
    }
  }
private boolean isFileSystemLocation(Location location)