Requires the current Subject to have been authenticated during their current session for the annotated
class/instance/method to be accessed or invoked.
Requires the current Subject to be a "guest", that is, they are not authenticated or remembered
from a previous session for the annotated class/instance/method to be accessed or invoked.
The permission string which will be passed to org.apache.shiro.subject.Subject#isPermitted(String)
to determine if the user is allowed to invoke the code protected by this annotation.