Access to page classes from App_Code

Hello,
Let's imagine I've a MasterPage MyMaster.master:
<%@ Master Language="C#" AutoEventWireup="true" CodeFile="MyMaster.master.cs" Inherits="MyMaster" ClassName="MyMaster" %>
 
to acccess some of the properties of this MasterPage from a Page, it's easy:
((MyMaster)Page.Master).MyProperty
 
The point is: how do I access to this MyMaster type from App_Code? I would like to cast some objects using this type:
 MyMaster myMaster=myObject as MyMaster;
 
 thanks for your help!

 
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