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 will be null if the intersection is empty.
Because two users never intersect, this method is not useful for System.Security.Permissions.PrincipalPermission. For example,
code reference: System.Security.Permissions.PrincipalPermission#1
is equivalent to
code reference: System.Security.Permissions.PrincipalPermission#2
because no identity can simultaneously represent both Bob and Louise. In effect, pp1.Demand() only succeeds if an unauthenticated principal (with name equal to the empty string ("")) is allowed to act in the Administrator role.