anchor.diff:      Req = ['ACR', {'Accounting-Record-Type', ?EVENT_RECORD},
                     {'Accounting-Record-Number', 4}],
   
  -    ?answer_message(?TOO_BUSY)
  -        = call(Config, Req).
  +    ['answer-message' | #{'Result-Code' := ?TOO_BUSY,
  +                          'AVP' := [OLR]}]
  +        = call(Config, Req),
  +
  +    #diameter_avp{name = 'OC-OLR',
  +                  value = #{'OC-Sequence-Number' := 1,
  +                            'OC-Report-Type' := 0,  %% HOST_REPORT
  +                            'OC-Reduction-Percentage' := [25],
  +                            'OC-Validity-Duration' := [60],
  +                            'AVP' := [OSF]}}
  +        = OLR,
  +    #diameter_avp{name = 'OC-Supported-Features',
  +                  value = #{} = Fs}
  +        = OSF,
  +    0 = maps:size(Fs).
   
   %% Send a 3xxx Experimental-Result in an answer not setting the E-bit
   %% and missing a Result-Code.
  
positive.code: send_ok(Config) ->
      Req = ['ACR', {'Accounting-Record-Type', ?EVENT_RECORD},
                    {'Accounting-Record-Number', 1}],
  
      ['ACA' | #{'Result-Code' := ?SUCCESS,
                 'Session-Id' := _}]
          = call(Config, Req).
  
negative.code: request(['ACR' | #{'Accounting-Record-Number' := 4}],
          #diameter_caps{origin_host = {OH, _},
                         origin_realm = {OR, _}}) ->
      %% Include a DOIC AVP that will be encoded/decoded because of
      %% avp_dictionaries config.
      OLR = #{'OC-Sequence-Number' => 1,
              'OC-Report-Type' => 0,  %% HOST_REPORT
              'OC-Reduction-Percentage' => [25],
              'OC-Validity-Duration' => [60],
              'AVP' => [{'OC-Supported-Features', []}]},
      Ans = ['answer-message', {'Result-Code', ?TOO_BUSY},
                               {'Origin-Host', OH},
                               {'Origin-Realm', OR},
                               {'AVP', [{'OC-OLR', OLR}]}],
      {reply, Ans};
  
  %% send_proxy_info
  