title: What is the use of 'abstract override' in C#?
body: <p>Just out of curiosity I tried overriding a abstract method in base class, and method the implementation abstract. As below:</p>
  
  <pre><code>public abstract class FirstAbstract
  {
      public abstract void SomeMethod();
  }
  
  public abstract class SecondAbstract : FirstAbstract
  {
      public abstract override void SomeMethod();
      //?? what sense does this make? no implementaion would anyway force the derived classes to implement abstract method?
  }
  </code></pre>
  
  <p>Curious to know why C# compiler allows writing 'abstract override'. Isn't it redundant? Should be a compile time error to do something like this. Does it serve to some use-case?</p>
  
  <p>Thanks for your interest.</p>