Rails ActiveAdmin - get current_admin_user in utility navigation? -

the activeadmin docs can override utility navigation this:

activeadmin.setup |config|   config.namespace :admin |admin|     admin.build_menu :utility_navigation |menu|       menu.add label: "activeadmin.info", url: "http://www.activeadmin.info", html_options: { target: :blank }       admin.add_logout_button_to_menu menu # can pass priority & html_options link_to use     end   end end 

it says default display includes current user's email address. how current user's email address? when try replacing menu.add label value current_admin_user error says current_admin_user undefined. how access info signed in user config file? how activeadmin behind scenes?

config.namespace :admin |admin|       admin.build_menu :utility_navigation |menu|          menu.add  :label  => proc{ display_name current_active_admin_user },                   :url    =>  proc{  edit_admin_admin_user_path(current_active_admin_user) }  ,#link_to current_active_admin_user,                   :id     => 'current_user',                   :if     => proc{ current_active_admin_user? }         admin.add_logout_button_to_menu menu       end     end