public async Task <IActionResult> UpdatePackage(string package, [FromBody] UpdatePackageViewModel vm)
        {
            if (!ModelState.IsValid || PackageUtils.UnescapeName(package) != vm.Name)
            {
                return(BadRequestResponse);
            }

            try {
                await _packageService.CommitAsync(vm.Name, ToPatch(vm));

                return(Ok("updated package"));
            }
            catch (DuplicatePackageVersionException) {
                return(DuplicateVersionResponse);
            }
            catch (PackageVersionNotFoundException nfe) {
                return(Error($"package version not found ({nfe.Identifier.Version})", HttpStatusCode.BadRequest));
            }
        }