@Test public void testRuleRefs() throws Exception {
        String action = "$lab.start; $c.text;";
		String expected = "(((AContext)_localctx).lab!=null?(((AContext)_localctx).lab.start):null); (((AContext)_localctx).c!=null?_input.getText(((AContext)_localctx).c.start,((AContext)_localctx).c.stop):null);";
		testActions(attributeTemplate, "inline", action, expected);
    }
Regression test for "in antlr v4 lexer, $ translation issue in action".
https://github.com/antlr/antlr4/issues/176
tool-testsuite/test/org/antlr/v4/test/tool/TestActionTranslation.java