anchor.diff:              |> Option.defaultValue {
                   IsArm = false
                   IsRef = false
  +                IsBox = false
                   HasMultipleUses = true }
           let isOnlyReference =
               if varAttrs.IsRef then false
  
positive.code: 
      let transformCallee (com: IRustCompiler) ctx calleeExpr =
          let ctx = { ctx with Typegen = { ctx.Typegen with TakingOwnership = false } }
          com.TransformAsExpr(ctx, calleeExpr)
  
      let isModuleMember (com: IRustCompiler) (callInfo: Fable.CallInfo) =
          match callInfo.CallMemberInfo with
  
negative.code:         let generics = makeGenerics fnGenParams
          let kind = mkFnKind header fnDecl generics (Some fnBodyBlock)
          let attrs = []
          let fnItem = mkFnItem attrs name kind |> mkNonPublicItem
          let scopedVarAttrs = {
              IsArm = false
              IsRef = false
              IsBox = true
              HasMultipleUses = true
          }
          let ctxNext = { ctx with ScopedSymbols = ctx.ScopedSymbols |> Map.add name scopedVarAttrs }
          mkItemStmt fnItem, ctxNext
  
      let transformModuleFunction (com: IRustCompiler) ctx (decl: Fable.MemberDecl) =
          let name = splitLast decl.Name
  