public async Task <BaGetRegistrationIndexResponse> GetRegistrationIndexOrNullAsync(
string packageId,
CancellationToken cancellationToken = default)
{
var packages = await _mirror.FindPackagesAsync(packageId, cancellationToken);
if (!packages.Any())
{
return(null);
}
return(_builder.BuildIndex(
new PackageRegistration(
packageId,
packages)));
}