} else { throw new IllegalArgumentException();
	public long getDateHeader(String name) {		//headers are stored as strings and must be converted		String date = getHeader(name);		if (date != null) {			HttpDate d = new HttpDate(date);			if (d.isValid()) {				return (d.getAsLong()); // Parsed OK, so get the value as a Long			} else {				throw new IllegalArgumentException();			}		}		return (-1);	}