@Override
	public Handle rule(GrammarAST ruleAST, String name, Handle blk) {
		Rule r = g.getRule(name);
		RuleStartState start = atn.ruleToStartState[r.index];
		epsilon(start, blk.left);
		RuleStopState stop = atn.ruleToStopState[r.index];
		epsilon(blk.right, stop);
		Handle h = new Handle(start, stop);
//		ATNPrinter ser = new ATNPrinter(g, h.left);
//		System.out.println(ruleAST.toStringTree()+":\n"+ser.asString());
		ruleAST.atnState = start;
		return h;
	}
ATN construction routines triggered by ATNBuilder.g.

 No side-effects. It builds an {@link ATN} object and returns it.
tool/src/org/antlr/v4/automata/ParserATNFactory.java