title: must declare a body because it's not marked abstract
body: <p>I have interface</p>
  <pre><code>INews.cs
  public interface INews{
     int Id {get; set;}
     string Name {get; set;}
     void Add(News news);
     void Remove(News news);
  }
  </code></pre>
  <p>and I have News.cs which implements that interface</p>
  <pre><code>public class News : INews {
    public int Id {get; set;}
    public string Name {get; set;}
    public void Add(News news);
    public void Remove(News news);
  </code></pre>
  <p>}</p>
  <p>on compile, I have the following message
  <strong>must declare a body because it's not marked abstract</strong></p>
  <p>is that mean that I should declare body inside the constructor of News class?</p>