anchor.diff:                  il.Emit(OpCodes.Callvirt, invoke)
                   il.Emit(OpCodes.Brfalse_S, unmatched)
           )
  +
       /// Generates method return
       let generateReturn
           (il:ILGenerator) (returnValues:ResizeArray<Value>,returnValuesField:FieldBuilder) (mi:MethodInfo,result) =
  
positive.code:     /// Returns true if method has specified attribute
      let hasAttribute a (mi:MethodInfo) = mi.GetCustomAttributes(a, true).Length > 0
      /// Converts expression to a tuple of MethodInfo and Arg array
      let toArgs args =        
          [|for arg in args ->
              match arg with
              | Call(_, mi, _) when hasAttribute typeof<WildcardAttribute> mi -> Any
  
negative.code:     /// Creates a generic instance of the abstract type
      static member With(f:'TAbstract -> Expr<_>) =
          let default' = Unchecked.defaultof<'TAbstract>
          let calls = toCallResult (typeof<'TAbstract>) (f default')
          Mock<'TAbstract>(MockMode.Strict, calls).Create()
  /// Generic builder for specifying method or property results
  and ResultBuilder<'TAbstract,'TReturnValue when 'TAbstract : not struct> 
  