set import problem

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.List;
import java.util.Set;
import java.util.HashMap;
import java.util.Map;

public class QuickFix {

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

  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
   Set<Video> allVideos = videosByTitle(course).valueSet();
    for (Video video : allVideos) {
     if (video.getTitle() == oldTitle) {
       videosByTitle(course).remove(oldTitle, video);
       videosByTitle(course).put(newTitle, video);
     }
   }
  }

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

}