@Override
  public byte @NotNull [] contentsToByteArray(@NotNull VirtualFile file) throws IOException {
    FSItem fsItem = convertAndCheck(file);
    if (!(fsItem instanceof FSFile)) throw new IOException("Not a file: " + file.getPath());
    return ((FSFile)fsItem).myContent;
  }
@Override
  public byte @NotNull [] contentsToByteArray(@NotNull VirtualFile file)