function t(a,b,c) {
	var f = $(b);
	var s = "";
	for ( var i = 0; i < f.length; i++ )
		s += (s && ",") + '"' + f[i].id + '"';
	isSet(f, q.apply(q,c), a + " (" + b + ")");
}
Asserts that a select matches the given IDs
@example t("Check for something", "//[a]", ["foo", "baar"]);
@result returns true if "//[a]" return two elements with the IDs 'foo' and 'baar'