Trying to migrate Shiro 2 in Jakarta EE - getting ShiroFilter$WrappedSecurityManager instead of own implementation of Security Manager

[Andrew G10i]

Trying to migrate to Shiro v2.x (from v1.13) and stuck with the following code 
(which was working fine in 1.13):

public static MySecurityManager getSecurityManager() {
    return (MySecurityManager) 
org.apache.shiro.SecurityUtils.getSecurityManager();
}

Getting the following exception:
java.lang.ClassCastException: class 
org.apache.shiro.ee.filters.ShiroFilter$WrappedSecurityManager cannot be cast 
to class pkg.local.MySecurityManager 
(org.apache.shiro.ee.filters.ShiroFilter$WrappedSecurityManager and 
pkg.local.MySecurityManager are in unnamed module of loader 
org.glassfish.web.loader.WebappClassLoader @26652402)

The issue is that some of my code need to iterate over realms, as result this 
code doesn't work anymore: getSecurityManager().getRealms().

Any suggestions how to get access to own custom implementation of Security 
Manager (MySecurityManager as per the code above) or at least get access to 
realms?

Thanks!