public String getDOT(ATNState startState, boolean isLexer) {
		Set<String> ruleNames = grammar.rules.keySet();
		String[] names = new String[ruleNames.size()+1];
		int i = 0;
		for (String s : ruleNames) names[i++] = s;
		return getDOT(startState, names, isLexer);
	}
This aspect is associated with a grammar
tool/src/org/antlr/v4/tool/DOTGenerator.java