title: Swagger default value for parameter
body: <p>How do I define default value for property in swagger generated from following API?</p>
  
  <pre><code>public class SearchQuery
  {
          public string OrderBy { get; set; }
  
          [DefaultValue(OrderDirection.Descending)]
          public OrderDirection OrderDirection { get; set; } = OrderDirection.Descending;
  }
  
  
  public IActionResult SearchPendingCases(SearchQuery queryInput);
  </code></pre>
  
  <p>Swashbuckle generates OrderDirection as required parameter. I would like to be it optional and indicate to client the default value (not sure if swagger supports this).</p>
  
  <p>I don't like making the property type nullable. Is there any other option? Ideally using built in classes...</p>
  
  <p>I use Swashbuckle.AspNetCore - <a href="https://docs.microsoft.com/en-us/aspnet/core/tutorials/web-api-help-pages-using-swagger?tabs=visual-studio" rel="noreferrer">https://docs.microsoft.com/en-us/aspnet/core/tutorials/web-api-help-pages-using-swagger?tabs=visual-studio</a></p>