After you uncomment the code in Main.java and Forum.java, fix the code as described in the comments of Main.java

public class Forum {
  private String topic;

  public Forum(String topic){
    this.topic = topic; 
  }

  public String getTopic() {
    return topic;
  }



  public void addPost(ForumPost post) {
    System.out.printf("A new post in %s topic from %s  about %s is available",

            post.getAuthor().getFirstName(),
            post.getAuthor().getLastName(),
            post.getTitle()
    );
  }

}

public class User {
  private String firstName;
  private String lastName;

  public User(String firstName, String lastName) {
    this.firstName = firstName; 
    this.lastName = lastName; 
  }

  public String getFirstName(){
    return firstName;
  }

  public String getLastName(){
    return lastName;
  }

}

public class ForumPost {
  private User author;
  private String title;
  private String description;

  public ForumPost(User author, String title, String description){
    this.author = author; 
    this.title = title; 
    this.description = description; 

  }

  public User getAuthor() {
    return author;
  }

  public String getTitle() {
    return title;
  }

  public String getDescription() {
    return description;
  }
}

public class Main {

  public static void main(String[] args) {
    System.out.println("Beginning forum example");
    if (args.length < 2) {
      System.out.println("Usage: java Main <first name> <last name>");
      System.err.println("<first name> and <last name> are required");
      System.exit(1);
    }

    Forum forum = new Forum("Java");

    String firstName = args[0];
    String lastName = args[1];
    User author = new User(firstName, lastName); 
    ForumPost post = new ForumPost(author, "title", "description");
    forum.addPost(post);


  }

}