anchor.diff:  methodFacet:
       httpMethod
       (
  -        SCALAR |
  +        empty=id |
           (
               MAP_START
                   methodBaseFacet*
  
positive.code:     );
  
  traitFacet:
      name=SCALAR
      (
          SCALAR |
          (
              MAP_START
                  methodBaseFacet*
  
negative.code: traitsFacet:
      'traits'
          (
              empty=id
              |   (
                      MAP_START
                      ( traitFacet )*
  