public Future<Frame> stream(boolean last, byte[] bytes, int off, int len) {
if (sendingFragment) {
if (last) {
sendingFragment = false;
}
return send(new BinaryFrame(Arrays.copyOfRange(bytes, off, off + len), true, last));
} else {
sendingFragment = !last;
return send(new BinaryFrame(Arrays.copyOfRange(bytes, off, off + len), false, last));
}
}