code: public QueryParamsMap get(String... keys) {
          QueryParamsMap ret = this;
          for (String key : keys) {
              if (ret.queryMap.containsKey(key)) {
                  ret = ret.queryMap.get(key);
              } else {
                  ret = NULL;
              }
          }
          return ret;
      }
docs: Returns an element from the specified key. <br>
  For querystring: <br>
  <br>
  user[name]=fede
  <br>
  <br>
  get("user").get("name").value() #  fede
  <br>
  or
  <br>
  get("user","name").value() #  fede
  
  @param keys The parameter nested key(s)
  @return the query params map