@Test
public void emptyTokens() throws Exception {
Grammar grammar = createMock(Grammar.class);
EmptyTokens tokens = createMock(EmptyTokens.class);
expect(tokens.eContainer()).andReturn(grammar);
expect(grammar.getName()).andReturn("G");
Antlr4Validator validator = PowerMock.createPartialMock(Antlr4Validator.class, "warning");