if (fromIndex > toIndex) throw new IllegalArgumentException(); for (int i = fromIndex; i < toIndex; i++) a[i] = val;
fill(a, 0, a.length, val);
  public static void fill(byte[] a, int fromIndex, int toIndex, byte val)  {    if (fromIndex > toIndex)      throw new IllegalArgumentException();    for (int i = fromIndex; i < toIndex; i++)      a[i] = val;  }