anchor.diff:  
   -export([space_user/0, space_manager/0, space_admin/0]).
   -export([group_user/0, group_manager/0, group_admin/0]).
  --export([space_privileges/0, group_privileges/0]).
  --export_type([space_privilege/0, group_privilege/0]).
  +-export([handle_service_user/0, handle_service_admin/0]).
  +-export([handle_user/0, handle_admin/0]).
  +-export([space_privileges/0, group_privileges/0, handle_service_privileges/0,
  +    handle_privileges/0]).
  +-export_type([space_privilege/0, group_privilege/0, handle_service_privilege/0,
  +    handle_privilege/0]).
   
   %% User privileges with regards to Space management.
   -type space_privilege() :: space_invite_user | space_remove_user |
  
positive.code: -spec group_privileges() -> [group_privilege()].
  group_privileges() ->
      group_admin().
  
negative.code: group_set_privileges | group_remove | group_leave_space |
  group_view_data | group_create_space_token |
  group_join_group | group_invite_group | group_remove_group.
  
  %% User privileges with regards to handle service.
  -type handle_service_privilege() :: register_handle_service |
  list_handle_services | delete_handle_service | modify_handle_service |
  view_handle_service.
  
  %% User privileges with regards to handle.
  -type handle_privilege() :: register_handle | list_handles | delete_handle |
  modify_handle | view_handle.
  
  %%%===================================================================
  %%% API
  