sS renderLineCompedSingleLevels(LineCompedSingle<Char> lc) {

  // each byte is the character's "color"

  // (0 for empty, 1 for color one, 2 for color two)

  byte[][] rows = renderLineCompedSingleLevels_raw(lc);

  S text = uncompressLineCompedSingle(lc);

  //printVars(+rows);

  int n = l(first(rows));

  ret lines(map(rows, row -> {

    StringBuilder buf = new(n);

    for i to n: {

      if (row[i] == 0) 

        buf.append(i == n-1 ? " " : "  ");

      else {

        buf.append(text.charAt(i));

        if (i < n-1)

          buf.append(row[i+1] != 0 && row[i+1] != row[i]

            ? '|' : ' ');

      }

    }

    ret str(buf);

  }));

}