@Override
    public void println(int logLevel, String tag, String msg) {
        for (Printer printer : printers) {
            printer.println(logLevel, tag, msg);
        }
    }
Constructor, pass printers in and will use all these printers to print the same logs.

@param printers the printers used to print the same logs
android/android_framework/base/src/main/java/com/elvishew/xlog/printer/PrinterSet.java