title: Cannot implicitly convert type Interface to 'System.Collections.Generic.IList<T>'
body: <p>stuck in below issue please help,
  I have one below class and it contain one method with return type is interface</p>
  
  <pre><code>public class Helper
  { 
      public IRestResponse GetCam (string searchTerm, int page, int pageSize)
      {
         RestRequest request = new RestRequest(Method.GET)
                               {
                                 RequestFormat = DataFormat.Json,
                                 Resource = string.Format("/assets/campaigns?search={0}&amp;page={1}&amp;count={2}&amp;depth=complete",
                                 searchTerm, page, pageSize)
                                };
  
        IRestResponse response = _client.Execute(request);
  
        return response;
      }
  }
  </code></pre>
  
  <p>in that interface I have some get set,</p>
  
  <pre><code>public interface IRestResponse
      {
          string Content { get; set; }
          string ContentEncoding { get; set; }
          long ContentLength { get; set; }
          string ContentType { get; set; }
          IList&lt;RestResponseCookie&gt; Cookies { get; }
          Exception ErrorException { get; set; }
          string ErrorMessage { get; set; }
          IList&lt;Parameter&gt; Headers { get; }
          IRestRequest Request { get; set; }
          ResponseStatus ResponseStatus { get; set; }
          Uri ResponseUri { get; set; }
  
      }
  }
  </code></pre>
  
  <p>Now when I call Helper class in my another program like below it giving me error as :</p>
  
  <blockquote>
    <blockquote>
      <p>"Cannot implicitly convert type 'RestSharp.IRestResponse' to 'System.Collections.Generic.IList>'. An explicit conversion exists (are you missing a cast?)"</p>
    </blockquote>
  </blockquote>
  
  <p>my calling program have below code</p>
  
  <pre><code>CamSample.Helper f = new CampaignHelper("Company name", "UserName", "Password", "SiteName");
  IList&lt;CampaignSample.Models.IRestResponse&gt; q = new List&lt;CampaignSample.Models.IRestResponse&gt;();
  //List&lt;IRestResponse&lt;CampaignSample.Models.Campaign&gt;&gt; w = new IList&lt;IRestResponse&lt;CampaignSample.Models.Campaign&gt;&gt;().ToList();
  q = f.GetCam("", 1, 200);
  </code></pre>
  
  <p>--- getting the error here
  Please tell me the solution </p>