Two code reported by LGTM, those issues need investigate

https://lgtm.com/projects/g/apache/dubbo/snapshot/001162d4f461e28561b01e2f90b15c1627706cf7/files/dubbo-common/src/main/java/org/apache/dubbo/common/config/Environment.java?sort=name&dir=ASC&mode=heatmap
https://lgtm.com/projects/g/apache/dubbo/snapshot/001162d4f461e28561b01e2f90b15c1627706cf7/files/dubbo-metadata/dubbo-metadata-processor/src/main/java/org/apache/dubbo/metadata/annotation/processing/rest/ServiceRestMetadataStorage.java?sort=name&dir=ASC&mode=heatmap
clearExternalConfigs();
        clearAppExternalConfigs();
    }
    public PropertiesConfiguration getPropertiesConfiguration() {
        return propertiesConfiguration;
    }
    public SystemConfiguration getSystemConfiguration() {
        return systemConfiguration;
    }
    public EnvironmentConfiguration getEnvironmentConfiguration() {
        return environmentConfiguration;
    }
    public InmemoryConfiguration getExternalConfiguration() {
        return externalConfiguration;
    }
    public InmemoryConfiguration getAppExternalConfiguration() {
        return appExternalConfiguration;
    }
    
    public void clearExternalConfigs() {
        this.externalConfiguration.clear();
        this.externalConfigurationMap.clear();
    }
    
    public void clearAppExternalConfigs() {
        this.appExternalConfiguration.clear();
        this.appExternalConfigurationMap.clear();
    }
}