@Override
    public Selector<List<T>, CmdbContext<T>, String> parse(String expression) throws NacosException {
        this.expression = expression;
        doParse(expression);
        return this;
    }
@Test
    void testParse() throws NacosException {
        MockCmdbSelector cmdbSelector = new MockCmdbSelector();
        cmdbSelector.parse("test");
        assertEquals("test", cmdbSelector.getExpression());
        assertEquals(1, counter.get());
    }