python - error site register django -

i have 2 classes in admin.py. because can't register them twice, don't know how fix problem. says: "register() takes @ 3 arguments (4 given)". code:

class tesi_availableadmin (admin.modeladmin):     model=tesi     fieldsets = (             (none, {                    'fields': ('teacher', 'title', 'description', 'date')                     }),              )       list_filter = ['date']     search_fields = ['teacher', 'title', 'description']      def queryset(self, request):         qs=super(tesi_availableadmin, self).queryset(request)         return qs.filter(state='available')  class tesi_requestadmin (admin.modeladmin):     models=tesi     fieldsets = (      (none, {         'fields': ('teacher', 'title', 'description', 'date', 'student')          }),     )     list_filter = ['date']     search_fields = ['teacher', 'title', 'description']       def queryset(self, request):         qs=super(tesi_requestadmin, self).queryset(request)         return qs.filter(state='request')  admin.site.register(tesi,tesi_availableadmin) admin.site.register(tesi_requestadmin) 

do know how can register classes? thank you!