anchor.diff:  %%--------------------------------------------------------------------
   %% @doc Admin privileges in OZ API.
   %%--------------------------------------------------------------------
  --spec oz_admin() -> [oz_privilege()].
  +-spec oz_admin() -> privileges(oz_privilege()).
   oz_admin() ->
  -    ordsets:union(
  -        oz_viewer(),
  -        ordsets:from_list([
  -            view_privileges,
  -            set_privileges,
  -
  -            add_member_to_space,
  -            remove_member_from_space
  -        ])
  -    ).
  +    union(oz_viewer(), [
  +        view_privileges,
  +        set_privileges,
  +
  +        add_member_to_space,
  +        remove_member_from_space
  +    ]).
   
   
   %%--------------------------------------------------------------------
   %% @doc All OZ API privileges.
  -%%--------------------------------------------------------------------
  --spec oz_privileges() -> [oz_privilege()].
  +%% @equiv oz_admin()
  +%%--------------------------------------------------------------------
  +-spec oz_privileges() -> privileges(oz_privilege()).
   oz_privileges() ->
       oz_admin().
   
  
positive.code: %%%===================================================================
  
  %%--------------------------------------------------------------------
  %% @doc A privilege level of a Space user.
  %%--------------------------------------------------------------------
  -spec space_user() -> [space_privilege()].
  space_user() ->
      ordsets:from_list([space_view_data, space_write_files]).
  
  %%--------------------------------------------------------------------
  %% @doc A privilege level of a Space manager.
  %%--------------------------------------------------------------------
  -spec space_manager() -> [space_privilege()].
  space_manager() ->
      ordsets:union(
          space_user(),
          ordsets:from_list([
              space_invite_user,
              space_remove_user,
              space_invite_group,
              space_remove_group,
              space_manage_shares
          ])
      ).
  
  %%--------------------------------------------------------------------
  %% @doc A privilege level of a Space administrator. This level contains all
  %% atoms representing space privileges.
  %% @end
  %%--------------------------------------------------------------------
  -spec space_admin() -> [space_privilege()].
  space_admin() ->
      ordsets:union(
          space_manager(),
          ordsets:from_list([
              space_add_provider,
              space_remove_provider,
              space_set_privileges,
              space_change_data,
              space_remove
          ])
      ).
  
  %%--------------------------------------------------------------------
  %% @doc All atoms representing space privileges.
  %% @equiv space_admin()
  %%--------------------------------------------------------------------
  -spec space_privileges() -> [space_privilege()].
  space_privileges() ->
      space_admin().
  
  
negative.code: -author("Konrad Zemek").
  -author("Lukasz Opiola").
  
  -type privileges(Type) :: ordsets:ordset(Type).
  
  %% User privileges with regards to Space management.
  -type space_privilege() :: space_invite_user | space_remove_user |
  space_invite_group | space_remove_group | space_set_privileges |
  