	@Test public void testMakePongIfPing() {

		String[][] cases = {
			{null, ""},
			{null, "PONG"},
			{null, "PINGU"},
			{null, " PING"},
			{null, " :abc PING"},
			{null, "PING:def"},
			{null, "abc WHAT PING"},
			{null, "STOPPING"},
			{null, ":nick!user@host PRIVMSG #chan :PING"},
			{"PONG", "PING"},
			{"PONG", ":prefix PING"},
			{"PONG ", ":pre   PING "},
			{"pong", "ping"},
			{"pONg", "pINg"},
			{"PONG abc def", "PING abc def"},
			{"PONG :hello world", "PING :hello world"},
			{"PONG  two   :three four", ":one  PING  two   :three four"},
			{"PONG PONG PING", "PING PONG PING"},
			{"pong PIng", ":PING ping PIng"},
		};
		for (String[] cs : cases)
			assertEquals(cs[0], makePong(cs[1]));
	}