class BlogPost {
  public String title;
  public String author;
  public String type;

  BlogPost(String title, String author, String type){
    this.author = author;
    this.title = title;
    this.type = type;
  }


  public static void main(String... args) {
    BlogPost p0 = new BlogPost("Title0", "Author0", "type0");
    BlogPost p1 = new BlogPost("Title1", "Author1", "type1");
    BlogPost p2 = new BlogPost("Title2", "Author2", "type2");
    BlogPost p3 = new BlogPost("Title3", "Author2", "type1");
    BlogPost p4 = new BlogPost("Title4", "Author0", "type2");
    BlogPost p5 = new BlogPost("Title5", "Author0", "type2");

    List<BlogPost> posts = Arrays.asList(p0, p1, p2, p3, p4, p5);

    Map<String, List<BlogPost>> grouped = posts.stream().collect(groupingBy(p -> p.author));

    Set<BlogPost> distinct = grouped.values().stream().map(ps -> ps.get(0)).collect(toSet());

    System.out.println(distinct);

  }

}