Method getSerialExecutor

app/src/main/java/eu/faircode/email/Helper.java:272–276

()

    private static ExecutorService sDownloadExecutor = null;

    static ExecutorService getSerialExecutor() {
        if (sSerialExecutor == null)
            sSerialExecutor = getBackgroundExecutor(1, "serial");
        return sSerialExecutor;
    }

    static ExecutorService getParallelExecutor() {
        if (sParallelExecutor == null)