title: How to extend DataRow and DataTable in C# with additional properties and methods?
body: <p>I would like create a custom DataRow that will have -let's say- a propery called IsCheapest.</p>
  
  <pre><code>public class RateDataRow : DataRow
  {
      protected internal RateDataRow(DataRowBuilder builder) : base(builder)
      {
      }
  
      public bool IsCheapest { get; set ;}
  }
  </code></pre>
  
  <p>And I want to have a new DataTable that contains only ***RateDataRow***s so that .NewDataRow() returns RateDataRow instance as a new row.</p>
  
  <p>what should be the implementation on the class that extends DataTable?</p>
  
  <p>Thanks,</p>