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Java Java Data Structures Efficiency! Changing Course

help on this one.

Can you please help me with the functions in the QuickFix.java over the next few tasks? I've included other code files for your reference only. I'm going to pass in this course to the addForgottenVideo method. For this task, can you please follow the TODO in the comments in the method?

package com.example.model;

import java.util.List;

public class Course {
  private String mName;
  private List<Video> mVideos; 

  public Course(String name, List<Video> videos) {
    mName = name;
    mVideos = videos;

  public String getName() {
    return mName;

  public List<Video> getVideos() {
    return mVideos;

package com.example.model;

public class Video {
  private String mTitle;

  public Video(String title) {
    mTitle = title;

  public String getTitle() {
    return mTitle;

  public void setTitle(String title) {
    mTitle = title;

import com.example.model.Course;
import com.example.model.Video;

import java.util.Map;

public class QuickFix {

  public void addForgottenVideo(Course course) {
    mTitleVideo video = new TitleVideo("The Beginning Bits");
    // TODO(1):  Create a new video called "The Beginning Bits"
   mVideos.addCourse("second video");
    // TODO(2):  Add to the course videos as the second video.

  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {


  public Map<String, Video> videosByTitle(Course course) {
    return null;


2 Answers

I think you need to have a look through this thread as that certainly covers off the challenge you're facing.


The first TODO will look something like:

Video video = new Video("The beginning bits");

I'm struggling with the second TODO, if I'm being honest, but I haven't done that course!

I'll have a look now.