Creates and returns a permission that is the intersection of the current permission and the specified permission.
A new permission that represents the intersection of the current permission and the specified permission. This new permission is null if the intersection is empty.
The intersection of two permissions is a permission that describes the set of operations they both describe in common. Specifically, it represents the least permissive values of System.Security.Permissions.UIPermissionWindow and System.Security.Permissions.UIPermissionClipboard from those in the current permission and the specified permission.