[Catalyst] what's a user_class?

[Ken Perl]

I am trying the sample application of authentication but got below
errors while starting the server, what's a user class?

[debug] Loaded Path actions:
.-------------------------------------+--------------------------------------.
| Path                                | Private                              |
+-------------------------------------+--------------------------------------+
| /books/delete                       | /books/delete                        |
| /books/form_create                  | /books/form_create                   |
| /books/form_create_do               | /books/form_create_do                |
| /books/list                         | /books/list                          |
| /books/url_create                   | /books/url_create                    |
'-------------------------------------+--------------------------------------'

[info] MyApp powered by Catalyst 5.7003
You must provide a user_class at /usr/share/perl5/Catalyst.pm line 862
Compilation failed in require at script/myapp_server.pl line 52.


-- 
perl -e 'print unpack(u,"62V5N\"FME;G\!E<FQ`9VUA:6PN8V]M\"\@``
")'