I'm having a .NET Web API. I wish to make it as CORS Platform. So, I referred
<http://www.asp.net/web-api/overview/security/enabling-cross-origin-requests-in-web-api>

In the above link they explained very well how to make the Web API CORS. In the link they are using **`ICorsPolicyProvider`**. 

I searched the net for ICorsPolicyProvider, I got a link <https://msdn.microsoft.com/en-us/library/system.web.http.cors(v=vs.118).aspx>, in the link they mentioned **`System.Web.Http.Cors Namespace`**

I searched the same in Reference Manager

[![enter image description here](https://i.stack.imgur.com/qB8Ij.jpg)](https://i.stack.imgur.com/qB8Ij.jpg)

Here I can't able to find the **`System.Web.Http.Cors Namespace`**. Kindly assist me how to include the referece **`System.Web.Http.Cors Namespace`**. I think this is a namespace from Microsoft, So, I didn't search in NuGet. Kindly assist me only in Microsoft.