public void addParam(String key, String value) {
        if (params == null) {
            params = new HashMap<String, String>();
        }
        params.put(key, value);
    }
@author Robert HG (254963746@qq.com) on 10/26/15.
lts-core/src/main/java/com/github/ltsopensource/cmd/HttpCmdRequest.java