expect(mode.getId()).andReturn("MODE");
expect(grammar.getType()).andReturn(GrammarType.LEXER);
expect(mode.getRules()).andReturn(rules);
expect(mode.eClass()).andReturn(eClass);
expect(eClass.getEStructuralFeature("id")).andReturn(feature);
expect(rule.isFragment()).andReturn(true);
PowerMock.expectPrivate(validator, "error",