@Override
    public Map<String, ConfigChangeItem> doParse(String oldContent, String newContent, String type) {
        Map<String, Object> oldMap = Collections.emptyMap();
        Map<String, Object> newMap = Collections.emptyMap();
        try {
            Yaml yaml = new Yaml(new SafeConstructor(new LoaderOptions()));
            if (StringUtils.isNotBlank(oldContent)) {
                oldMap = yaml.load(oldContent);
                oldMap = getFlattenedMap(oldMap);
            }
            if (StringUtils.isNotBlank(newContent)) {
                newMap = yaml.load(newContent);
                newMap = getFlattenedMap(newMap);
            }
        } catch (MarkedYAMLException e) {
            handleYamlException(e);
        }
        
        return filterChangeData(oldMap, newMap);
    }
@Test
    void testRemoveKey() throws IOException {
        Map<String, ConfigChangeItem> map = parser.doParse("app:\n  name: nacos", "", type);
        assertEquals("nacos", map.get("app.name").getOldValue());
        assertNull(map.get("app.name").getNewValue());
    }