static FileDownloadSpec BuildSpec(MultiMirrorFileDownloadSpec spec, Uri host) => spec.Progress == null
? new FileDownloadSpec(spec.GetUri(host), spec.LocalFile)
{
Verification = spec.Verification,
CancellationToken = spec.CancellationToken,
ExistingFile = spec.ExistingFile
}
: new FileDownloadSpec(spec.GetUri(host), spec.LocalFile, spec.Progress)
{
Verification = spec.Verification,
CancellationToken = spec.CancellationToken,
ExistingFile = spec.ExistingFile
};
