library/src/main/java/com/liulishuo/filedownloader/FileDownloadList.java
void addUnchecked(final BaseDownloadTask.IRunningTask task) {
        if (task.isMarkedAdded2List()) {
            return;
        }

        synchronized (mList) {
            if (mList.contains(task)) {
                FileDownloadLog.w(this, "already has %s", task);
            } else {
                task.markAdded2List();
                mList.add(task);
                if (FileDownloadLog.NEED_LOG) {
                    FileDownloadLog.v(this, "add list in all %s %d %d", task,
                            task.getOrigin().getStatus(), mList.size());
                }
            }
        }
    }
void addUnchecked(final BaseDownloadTask.IRunningTask task) {
        if (task.isMarkedAdded2List()) {
            return;
        }

        synchronized (mList) {
            if (mList.contains(task)) {
                FileDownloadLog.w(this, "already has %s", task);
            } else {
                task.markAdded2List();
                mList.add(task);
                if (FileDownloadLog.NEED_LOG) {
                    FileDownloadLog.v(this, "add list in all %s %d %d", task,
                            task.getOrigin().getStatus(), mList.size());
                }
            }
        }
    }
This method generally used for enqueuing the task which will be assembled by a queue.

@see BaseDownloadTask.InQueueTask#enqueue()