library/src/main/java/com/liulishuo/filedownloader/util/FileDownloadSerialQueue.java
public void resume() {
        synchronized (finishCallback) {
            if (!paused) {
                FileDownloadLog.w(this, "require resume this queue(remain %d), but it is"
                        + " still running", mTasks.size());
                return;
            }

            paused = false;
            mTasks.addAll(pausedList);
            pausedList.clear();

            if (workingTask == null) {
                sendNext();
            } else {
                workingTask.addFinishListener(finishCallback);
                workingTask.start();
            }
        }
    }
public void resume() {
        synchronized (finishCallback) {
            if (!paused) {
                FileDownloadLog.w(this, "require resume this queue(remain %d), but it is"
                        + " still running", mTasks.size());
                return;
            }

            paused = false;
            mTasks.addAll(pausedList);
            pausedList.clear();

            if (workingTask == null) {
                sendNext();
            } else {
                workingTask.addFinishListener(finishCallback);
                workingTask.start();
            }
        }
    }
Resume the queue if the queue is paused.

@see #pause()