true if the current permission is a subset of the specified permission; otherwise, false.
The current permission is a subset of the specified permission if all demands that succeed for the current permission also succeed for the specified permission. That is, the specified permission contains at least the permissions contained in the subset. For UIPermission.IsSubsetOf(System.Security.IPermission) to return true, both the System.Security.Permissions.UIPermissionWindow and System.Security.Permissions.UIPermissionClipboard values of the current permission must be equal to or less permissive than the values of the specified permission.