final BufferedReadableByteChannel b = new BufferedReadableByteChannel(in);
b.mark(4);
ByteOrder order = PcapInputCapture.checkFormat(b);
b.reset();
return t.cast(new PcapInputCapture(b, order, filter));
} else if (t == SnoopInput.class) {
return t.cast(new SnoopInputCapture(in, filter));
}