diff --git a/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/TaskOpMode.java b/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/TaskOpMode.java
index 0aed31b53f31..b154f72bb809 100644
--- a/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/TaskOpMode.java
+++ b/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/TaskOpMode.java
@@ -59,6 +59,16 @@ public int registerTask(Task task) {
         return registerTask(task, -1);
     }
 
+    /**
+     * Register a task in the task map. All the tasks in the map will be iterated in
+     * the main loop when it's the right time to do.
+     *
+     * @param task         the task that need registering.
+     * @param linkedTaskId the taskId of the linked task. The task being registered will
+     *                     be run after the linked task is finished. If nothing provided,
+     *                     the registered task will start to run immediately.
+     * @return the taskId of the registered task.
+     */
     public int registerTask(Task task, int linkedTaskId) {
         task.init();
         int taskId = findMinFreeTaskId();
@@ -67,6 +77,11 @@ public int registerTask(Task task, int linkedTaskId) {
         return taskId;
     }
 
+    /**
+     * Cancel the task and all the linked-after tasks if necessary.
+     *
+     * @param taskId the taskId of the task needs canceling.
+     */
     public void cancelTask(int taskId) {
         Task task = tasks.get(taskId);
         if (task == null) return;
diff --git a/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/hardware/TimedServo.java b/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/hardware/TimedServo.java
index 1449a6e5260c..f5f6a641ecc7 100644
--- a/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/hardware/TimedServo.java
+++ b/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/hardware/TimedServo.java
@@ -89,6 +89,15 @@ public void scaleRange(double min, double max) {
         servo.scaleRange(min, max);
     }
 
+    /**
+     * Sets the current position of the servo in a fixed time, expressed as a fraction of
+     * its available range. If PWM power is enabled for the servo, the servo will attempt
+     * to move to the indicated position.
+     *
+     * @param position the position to which the servo should move, a value in the range [0.0, 1.0]
+     * @param timeMs   the time that the servo will take to move.
+     * @return a Task object
+     */
     public Task setPosition(double position, long timeMs) {
         final double delta = position - servo.getPosition();
         final long iterationCount = timeMs / Task.TICK_MS;
diff --git a/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/task/Task.java b/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/task/Task.java
index efe228aa534e..2ced8b70b134 100644
--- a/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/task/Task.java
+++ b/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/task/Task.java
@@ -3,16 +3,33 @@
 public interface Task {
     int TICK_MS = 50;
 
+    /**
+     * This method is called in the main loop of OpMode
+     * It should contain the code of EACH TICK, instead of a loop in it!
+     */
+    void iterate();
+
+    /**
+     * To judge whether the task needs to continue.
+     * @return Return true when it need to continue, otherwise false.
+     */
+    boolean hasNext();
+
+    /**
+     * This method is called when the task is registered in the TaskOpMode.
+     */
     default void init() {
     }
 
-    void iterate();
-
+    /**
+     * The method is called when the task is finished.
+     */
     default void finish() {
     }
 
-    boolean hasNext();
-
+    /**
+     * The method is called when the task is canceled.
+     */
     default void cancel() {
     }
 }