anchor.diff:      ;
   
   securedBy:
  -    name=SCALAR |
  +    name=id |
           (   MAP_START
  -                name=SCALAR?
  -                ( SCALAR | parameters=objectInstance)?
  +                ( empty=id | parameters=objectInstance)?
               MAP_END
           )
       ;
  
positive.code:     ;
  
  securitySchemeTypeFacet:
      'type' type=SCALAR
      ;
  
  securitySchemeSettingsFacet:
  
negative.code: bodyContentTypeFacet:
      contentType=SCALAR
          (
              empty=id
              |   (
                      MAP_START
                          bodyFacets
  