private void validate(ConfigType configType, ConfigItem configItem) {
        if (null == configType || null == configItem) {
            throw new IllegalArgumentException(String.format(
                "ConfigType {%s}, ConfigItem {%s} should not be null!", configType, configItem));
        }
    }
use a hash map to store the user configs with different config types and config items.
src/main/java/com/alipay/remoting/config/configs/DefaultConfigContainer.java