sclass JE_RepByte extends JEInstantCompressor {
  scaffolded public S compress(LByte data) {
    if (empty(data)) null;
    byte b = first(data);
    int n = l(data);
    for (int i = 1; i < n; i++)
      if (data.get(i) != b)
        null;
    ret formatFunctionCall repByte(n, b);
  }
}