public void
jump(int index) {
	if (index > pos) {
		throw new IllegalArgumentException("cannot jump past " +
						   "end of data");
	}
	pos = index;
}
Resets the current position of the output stream to the specified index.
@param index The new current position.
@throws IllegalArgumentException The index is not within the output.
src/main/java/core/org/xbill/DNS/DNSOutput.java