anchor.diff:  }).
   -record(atm_value_compress_expand_testcase, {
       data_spec,
  -    values
  +    values :: [
  +        Term :: json_utils:json_term() |
  +        {different, Input :: json_utils:json_term(), ExpOutput :: json_utils:json_term()} |
  +        {error, Input :: json_utils:json_term(), ExpError :: errors:error()}
  +    ]
   }).
   
   
  
positive.code:                 % atm_file_type is but a reference to underlying file entity -
                  % as such expanding it should fetch all current file attributes
                  {
                      #{<<"file_id">> => ?ok(file_id:guid_to_objectid(Guid))},
                      file_middleware_plugin:file_attrs_to_json(FileAttrs)
                  }
  
negative.code: 
              % Array items should be compressed and expanded according to their type rules
              {
                  different,
                  [
                      [],
                      [
  