@Test public void testCaseInsensitiveInCombinedGrammar() throws Exception {
		String grammar =
				"grammar CaseInsensitiveGrammar;\n" +
				"options { caseInsensitive = true; }\n" +
				"e\n" +
				"    : ID\n" +
				"    | 'not' e\n" +
				"    | e 'and' e\n" +
				"    | 'new' ID '(' e ')'\n" +
				"    ;\n" +
				"ID: [a-z_][a-z_0-9]*;\n" +
				"WS: [ \\t\\n\\r]+ -> skip;";

		String input = "NEW Abc (Not a AND not B)";
		ExecutedState executedState = execParser(
				"CaseInsensitiveGrammar.g4", grammar,
				"CaseInsensitiveGrammarParser", "CaseInsensitiveGrammarLexer",
				"e", input, false);
		assertEquals("", executedState.output);
		assertEquals("", executedState.errors);
	}
This is a regression test for antlr/antlr4#672 "Initialization failed in
locals".
https://github.com/antlr/antlr4/issues/672
tool-testsuite/test/org/antlr/v4/test/tool/TestParserExec.java