anchor.diff:        _AdditionalProperties = jsonschema:keyword(Schema, "additionalProperties", {}),
   
   
  -            ReqProps = [P || P <- Properties, lists:member(P, Required)],
  -            OptProps = [P || P <- Properties, not lists:member(P, Required)],
  +            ReqProps = [{P,S} || {P,S} <- Properties, lists:member(P, Required)],
  +            OptProps = [{P,S} || {P,S} <- Properties, not lists:member(P, Required)],
   
               %% case AdditionalProperties of 
               %%     false -> 
  
positive.code:                                             Optionals
                          ]
                        }));
           
          
          %% string
          %%     A JSON string.
  
negative.code:                 false -> Min = MinProperties - length(ReqProps)
              end,
              Max = MaxProperties - length(ReqProps),
              
              ?LET({PatternGen,AdditionalGen}, {create_patterns(PatternProperties),[]},
                   ?LET(Optionals, 
                        choose_properties(OptProps ++ lists:concat(PatternGen) ++ AdditionalGen , Min, Max),    
  
                        {
                          struct,
  