anchor.diff:      abstract Visit<'T1, 'T2, 'T3> : unit -> 'R
   
   type IShapeTuple3 =
  +    inherit IShapeTuple
       abstract Accept : ITuple3Visitor<'R> -> 'R
   
   type ShapeTuple<'T1, 'T2, 'T3> () =
  
positive.code:     abstract Visit<'T1, 'T2, 'T3, 'T4, 'T5, 'T6, 'T7, 'TRest> : unit -> 'R
  
  type IShapeTuple8 =
      abstract Accept : ITuple8Visitor<'R> -> 'R
  
  type ShapeTuple<'T1, 'T2, 'T3, 'T4, 'T5, 'T6, 'T7, 'TRest> () =
  
negative.code:     abstract Visit<'T1, 'T2, 'T3, 'T4, 'T5, 'T6> : unit -> 'R
  
  type IShapeTuple6 =
      inherit IShapeTuple
      abstract Accept : ITuple6Visitor<'R> -> 'R
  
  type ShapeTuple<'T1, 'T2, 'T3, 'T4, 'T5, 'T6> () =
  