@Test public void testFailedPredicateExceptionState() throws Exception {
		String grammar = load("Psl.g4");
		ExecutedState executedState = execParser("Psl.g4", grammar,
				"PslParser", "PslLexer", "floating_constant", " . 234", false);
		assertEquals("", executedState.output);
		assertEquals("line 1:6 rule floating_constant DEC:A floating-point constant cannot have internal white space\n", executedState.errors);
	}
This is a regression test for antlr/antlr4#588 "ClassCastException during
semantic predicate handling".
https://github.com/antlr/antlr4/issues/588
tool-testsuite/test/org/antlr/v4/test/tool/TestParserExec.java