public void analyze(ConnectContext context) {
        dbName = AnalyzerUtils.getOrDefaultDatabase(dbName, context);
        FeNameFormat.checkLabel(labelName);
    }
@Test(expected = SemanticException.class)
    public void testNoDb() throws SemanticException {
        new Expectations() {
            {
                analyzer.getDefaultDb();
                minTimes = 0;
                result = null;
            }
        };

        LabelName label = new LabelName("", "testLabel");
        label.analyze(new ConnectContext());
        Assert.fail("No exception throws");
    }