* Range#isConnected(Range) disconnected} ranges of type {@code C}.
 *
 * <p>Implementations that choose to support the {@link #add(Range)} operation are required to
 * ignore empty ranges and coalesce connected ranges. For example:
 *
 * {@snippet :
 * RangeSet<Integer> rangeSet = TreeRangeSet.create();
 * rangeSet.add(Range.closed(1, 10)); // {[1, 10]}

		participle.CaseInsensitive("Keyword"),
		participle.CaseInsensitive("Timeword"),
	)

	validCases := []string{
		"count(*)",
		"sum(2 + s.id)",
		"sum(t)",
		"avg(s.id[1])",
		"coalesce(s.id[1], 2, 2 + 3)",

		"cast(s as string)",
		"cast(s AS INT)",
		"cast(s as DECIMAL)",
		"extract(YEAR from '2018-01-09')",
		"extract(month from '2018-01-09')",

		"extract(hour from '2018-01-09')",