code: public File writeMap(Map<?, ?> map, LineSeparator lineSeparator, String kvSeparator, boolean isAppend) throws IORuntimeException {
  		if(null == kvSeparator) {
  			kvSeparator = " = ";
  		}
  		try(PrintWriter writer  = getPrintWriter(isAppend)) {
  			for (Entry<?, ?> entry : map.entrySet()) {
  				if (null != entry) {
  					writer.print(StrUtil.format("{}{}{}", entry.getKey(), kvSeparator, entry.getValue()));
  					printNewLine(writer, lineSeparator);
  					writer.flush();
  				}
  			}
  		}
  		return this.file;
  	}
docs: 将Map写入文件，每个键值对为一行，一行中键与值之间使用kvSeparator分隔
  
  @param map Map
  @param lineSeparator 换行符枚举（Windows、Mac或Linux换行符）
  @param kvSeparator 键和值之间的分隔符，如果传入null使用默认分隔符" = "
  @param isAppend 是否追加
  @return 目标文件
  @throws IORuntimeException IO异常
  @since 4.0.5