docs: public static HashMap<String, String> decodeParamMap(String paramsStr, String charset) {
  		final Map<String, List<String>> paramsMap = decodeParams(paramsStr, charset);
  		final HashMap<String, String> result = MapUtil.newHashMap(paramsMap.size());
  		List<String> valueList;
  		for (Entry<String, List<String>> entry : paramsMap.entrySet()) {
  			valueList = entry.getValue();
  			result.put(entry.getKey(), CollUtil.isEmpty(valueList) ? null : valueList.get(0));
  		}
  		return result;
  	}