static CachedFileType forType(@NotNull FileType fileType) {
    long stamp = ourInternerLock.readLock();
    try {
      return ourInterner.computeIfAbsent(fileType, CachedFileType::new);
    } finally {
      ourInternerLock.unlockRead(stamp);
    }
  }
static CachedFileType forType(@NotNull FileType fileType)