code: public void
  writeByteArray(byte [] b, int off, int len) {
  	need(len);
  	System.arraycopy(b, off, array, pos, len);
  	pos += len;
  }
docs: Writes a byte array to the stream.
  @param b The array to write.
  @param off The offset of the array to start copying data from.
  @param len The number of bytes to write.