public void removeExpired() {

        // Remove expired data from denylist
        Iterator<Map.Entry<String, UserData>> current = denylist.entrySet().iterator();
        while (current.hasNext()) {

            // Remove entry from map if its associated with expired data
            Map.Entry<String, UserData> entry = current.next();
            if (entry.getValue().isExpired())
                current.remove();
            
        }

    }
Removes all expired UserData objects from the denylist. This will
automatically be invoked whenever new UserData is added to the denylist.
extensions/guacamole-auth-json/src/main/java/org/apache/guacamole/auth/json/user/UserDataDenylist.java