anchor.diff:  -include_lib("ctool/include/privileges.hrl").
   -include_lib("ctool/include/api_errors.hrl").
   
  --export([fetch_entity/1, operation_supported/3]).
  +-export([fetch_entity/1, operation_supported/3, is_subscribable/2]).
   -export([create/1, get/2, update/1, delete/1]).
  --export([exists/2, authorize/2, validate/1]).
  +-export([exists/2, authorize/2, required_admin_privileges/1, validate/1]).
   
   %%%===================================================================
   %%% API
  
positive.code: operation_supported(get, configuration, _) -> true;
  
  operation_supported(_, _, _) -> false.
  
  
  %%--------------------------------------------------------------------
  
negative.code: 
  %%--------------------------------------------------------------------
  %% @doc
  %% Returns list of admin privileges needed to perform given operation.
  %% @end
  %%--------------------------------------------------------------------
  -spec required_admin_privileges(entity_logic:req()) -> [privileges:oz_privilege()] | forbidden.
  required_admin_privileges(_) -> [].
  
  
  %%--------------------------------------------------------------------
  %% @doc
  %% Returns validity verificators for given request.
  %% Returns a map with 'required', 'optional' and 'at_least_one' keys.
  %% Under each of them, there is a map:
  