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Challenge Task 3, final challenge at the end of Java Data Structures- why is my fixVideoTitle method not working?

Hi everyone,

I'm currently looking at the following challenge, specifically task 3:

"Finally, lets finish that final method fixVideoTitle. I will pass in the course, the current title, and the title I want to change it to. Hey you should totally use that videosByTitle map to help you find the video!"

Whilst I've managed to complete it now, why does my strategy NOT work? I assumed that the replace method I've took from the HashMap documentation would fit the bill perfectly, but not so it seems?

I assume it is because the method requires input of

(Course course, String oldTitle, String newTitle)

But I've tried to feed it a title, which is not a Course? Is there any way I could use the replace method on HashMaps to complete this task?

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

import java.util.HashMap;
import java.util.Map;

public class QuickFix {

  public void addForgottenVideo(Course course) {
    // TODO(1):  Create a new video called "The Beginning Bits"
      Video newVideo = new Video("The Beginning Bits");
    // TODO(2):  Add the newly created video to the course videos as the second video.
      course.getVideos().add(1, newVideo);

    public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
            for (Video video : course.getVideos()) {
        videosByTitle.replace(video.getTitle(), oldTitle, newTitle);

  public Map<String, Video> videosByTitle(Course course) {
    Map<String, Video> byTitle = new HashMap<>();
      for(Video video : course.getVideos()) {
        byTitle.put(video.getTitle(), video);
    return byTitle;