// Don't return a size for directories or symbolic links; their sizes are implementation
      // specific and they can't be read as bytes using the read methods anyway.
      if (attrs.isDirectory() || attrs.isSymbolicLink()) {
        return Optional.absent();
      }

      return Optional.of(attrs.size());
    }

    @Override
    public long size() throws IOException {

      // Don't return a size for directories or symbolic links; their sizes are implementation
      // specific and they can't be read as bytes using the read methods anyway.
      if (attrs.isDirectory() || attrs.isSymbolicLink()) {
        return Optional.absent();
      }

      return Optional.of(attrs.size());
    }

    @Override
    public long size() throws IOException {

      MoreFiles.deleteRecursively(file);

      assertFalse(Files.exists(file, NOFOLLOW_LINKS));

      Path symlink = fs.getPath("/symlinktodir");
      assertTrue(Files.isSymbolicLink(symlink));

      Path realSymlinkTarget = symlink.toRealPath();
      assertTrue(Files.isDirectory(realSymlinkTarget, NOFOLLOW_LINKS));

      MoreFiles.deleteRecursively(symlink);