code: public static void error(Object obj) {
  		if (obj instanceof Throwable) {
  			Throwable e = (Throwable) obj;
  			error(e, e.getMessage());
  		} else {
  			error("{}", obj);
  		}
  	}
docs: 同 System.err.println()方法，打印控制台日志
  
  @param obj 要打印的对象