public async Task ListVersions() { // Find all versions of a package (including unlisted versions). var client = new NuGetClient("https://api.nuget.org/v3/index.json"); var packageVersions = await client.ListPackageVersions("Newtonsoft.Json", includeUnlisted : true); if (!packageVersions.Any()) { Console.WriteLine($"Package 'Newtonsoft.Json' does not exist"); return; } Console.WriteLine($"Found {packageVersions.Count} versions"); }