sclass Test_ByteArraysPartialInputStream {
  new ByteArraysPartialInputStream stream;
  int n = 1000, nRanges = 10;
  byte[] data;
  int markPos;
  L<IntRange> ranges;
  
  public void run() ctex {
    data = randomBytes(n);
    ranges = splitIntoRandomRanges(nRanges, IntRange(0, n));
    markPos = middleElement(ranges).start;
    print(n2(ranges, "range") /*+ " (" + ranges + ")"*/ + ", markPos=" + markPos);
    for (r : ranges) {
      stream.write(subByteArray(data, r));
      if (r.start == markPos)
        stream.mark(n);
    }
    print("Wrote");
    
    print("Reading " + n);
    for i to n: 
      assertEquals(ubyteToInt(data[i]), stream.read());
    assertEquals(-1, stream.read());
    
    print("Resetting to " + markPos);
    stream.reset();
    for (int i = markPos; i < n; i++)
      assertEquals(ubyteToInt(data[i]), stream.read());
    assertEquals(-1, stream.read());
    
    print("Read OK");
  }
}