title: Force abstract implementation to child of child
body: <p>I want something like this </p>
  
  <pre><code>    public abstract class abc
      {
          public abstract void test();
      }
  
      public class def : abc
      {
              // ignore test(), this is concrete class which can be initialized
              // test method is not needed for this class
      }
  
      public class ghi : def
      {
          public override void test()
          {
              // force test method implementation here
          }
      }
  </code></pre>
  
  <p>What are possible ways to do that. I want to ignore use of interface at GHI class as these are not under our application.</p>
  
  <p><strong>Edit</strong></p>
  
  <p>All of you are correct, but I need similar implementation. Point is I have various objects which has common functionality so I inherited from a class. I want to give this class to other ppl who must implement test method. </p>