private static void addIntervalForCategory(
			Map<String, IntervalSet> categoryMap,
			String categoryName,
			int start,
			int finish) {
		IntervalSet intervalSet = categoryMap.get(categoryName);
		if (intervalSet == null) {
			intervalSet = new IntervalSet();
			categoryMap.put(categoryName, intervalSet);
		}
		intervalSet.add(start, finish);
	}
StringTemplate controller used to generate parameters to feed
to {@code unicodedata.st} to code-generate {@code UnicodeData.java},
used by the tool for Unicode property escapes like {@code \\p\{Lu\}}.

Uses ICU to iterate over Unicode character categories, properties,
and script codes, as well as aliases for those codes.

This class exists in its own Maven module to avoid adding a
dependency from the tool onto the (large) ICU runtime.
tool/src/org/antlr/v4/unicode/UnicodeDataTemplateController.java