anchor.diff:  encode(MsgFields = [{FieldName1, _Value} | _], #field{type = Type, presence = Presence, name = FieldName2, operator = #tail{}},
      Context = #context{pmap = PMap})
   when (FieldName1 =/= FieldName2) ->
  -   {encode_type(Type, null, is_nullable(Presence)), MsgFields, Context#context{pmap = <<PMap/bits, 0:1>>}};
  +   {encode_type(Type, null, is_nullable(Presence)), MsgFields, Context#context{pmap = <<PMap/bits, 1:1>>}};
   
   encode([{FieldName1, Value} | MsgFieldsRest], #field{type = Type, presence = Presence, name = FieldName2, operator = #tail{}},
      Context = #context{pmap = PMap})
   when ((FieldName1 == FieldName2) andalso (Value == absent)) ->
  -   {encode_type(Type, null, is_nullable(Presence)), MsgFieldsRest, Context#context{pmap = <<PMap/bits, 0:1>>}};
  +   {encode_type(Type, null, is_nullable(Presence)), MsgFieldsRest, Context#context{pmap = <<PMap/bits, 1:1>>}};
   
   encode([{_, Value} | MsgFieldsRest],
      #field{type = Type, presence = Presence, operator = #tail{dictionary = D, key = Key, value = InitialValue}},
  
positive.code:       undef ->
           Dicts1 = erlang_fast_dicts:put_value(Dict, Key, Value, Dicts),
           {encode_type(Type, Value, is_nullable(Presence)), MsgFieldsRest, Context#context{pmap = <<PMap/bits, 1:1>>, dicts = Dicts1}};
        Value ->
           {<<>>, MsgFieldsRest, Context#context{pmap = <<PMap/bits, 0:1>>}};
        DictValue when (Value =/= DictValue) ->
  
negative.code:    #field{type = Type, name = FieldName2, presence = Presence, operator = #default{value = InitialValue}},
        Context = #context{pmap = PMap}) ->
     case Presence of
        optional when (FieldName1 =/= FieldName2) andalso (InitialValue == undef) ->
           {<<>>, MsgFields, Context#context{pmap = <<PMap/bits, 0:1>>}};
        optional when (FieldName1 == FieldName2) andalso (Value == absent) andalso (InitialValue == undef) ->
           {<<>>, MsgFieldsRest, Context#context{pmap = <<PMap/bits, 0:1>>}};
        optional when (FieldName1 =/= FieldName2) ->
           {encode_type(Type, null, true), MsgFields, Context#context{pmap = <<PMap/bits, 1:1>>}};
        optional when (FieldName1 == FieldName2) andalso (Value == absent) ->
           {encode_type(Type, null, true), MsgFieldsRest, Context#context{pmap = <<PMap/bits, 1:1>>}};
        _ when (FieldName1 == FieldName2) andalso (Value =/= InitialValue) ->
           {encode_type(Type, Value, is_nullable(Presence)), MsgFieldsRest, Context#context{pmap = <<PMap/bits, 1:1>>}};
        _ when (FieldName1 == FieldName2) andalso (Value == InitialValue) ->
  