sclass ByteArraysPartialInputStream extends InputStream {
  sclass State {
    int ofs;
    MinimalChain<byte[]> chain;
    
    *(int *ofs, MinimalChain<byte[]> *chain) {}
  }
  
  bool eof;
  MinimalChain<byte[]> last = new(null);
  State state = new(0, last);
  long absolutePosition;

  public synchronized int read() throws IOException {
    while ping (true) {
      if (state.ofs < l(state.chain))
        ret state.chain![state.ofs++];
    
      if (state.chain.next == null)
        ret -1;
      
      state = new State(0, state.chain.next);
    }
  }
  
  public synchronized void add(byte[] buffer) {
    last.setNext(new MinimalChain(null));
    last.setElement(buffer);
    last = last.next;
  }
  
  public void addEOF() {
    eof = true;
  }
  
  public bool isEOF() {
    ret state.head == last && eof;
  }
  
  @Override public bool markSupported() { true; }
  
  @Override public void mark(int readLimit) {
    mark = position;
    in.mark(readLimit);
  }
  
  @Override public void reset() throws IOException {
    if (mark < 0) fail();
    position = mark;
    mark = -1;
    in.reset();
  }
  
  toString { ret renderVars SimulatedPartialInputStream(+streamEnded, +position, +cutOffPoint, +mark); }
}