What is missing in this code? I put the curly brace and I'm still getting the error. Help!

package com.example.model;

import java.util.List;
import java.util.ArrayList;
import java.util.Set;
import java.util.HashSet;


public class Course {
  private String mTitle;
  private Set<String> mTags;

  public Course(String title) {
    mTitle = title;
    mTags = new HashSet<String>();
    // TODO: initialize the set mTags
  }

  public void addTag(String tag) {
    // TODO: add the tag
    mTags.add(new String(tag));
  }

   public void addTags(List<String> tags) {
    // TODO: add all the tags passed in
    mTags.addAll(tags);
    }
  public boolean hasTag(String tag) {
    // TODO: Return whether or not the tag has  been added
    if (mTags.contains(tag)) {
      System.out.println("Tag exists");
    }
    return true;
   }
  public String getTitle() {
    return mTitle;
}