private IList <PackageSource> GetEndpointsAsync()
        {
            List <PackageSource> configurationSources = SourceProvider.LoadPackageSources()
                                                        .Where(p => p.IsEnabled)
                                                        .ToList();

            IList <PackageSource> packageSources;

            if (Source.Count > 0)
            {
                packageSources = Source
                                 .Select(s => PackageSourceProviderExtensions.ResolveSource(configurationSources, s))
                                 .ToList();
            }
            else
            {
                packageSources = configurationSources;
            }
            return(packageSources);
        }
        private static IEnumerable <PackageSource> GetPackageSources(ISettings settings, IEnumerable <string> sources, CommandOption config)
        {
            var availableSources = PackageSourceProvider.LoadPackageSources(settings).Where(source => source.IsEnabled);
            var uniqueSources    = new HashSet <string>();

            var packageSources = new List <PackageSource>();

            foreach (var source in sources)
            {
                if (!uniqueSources.Contains(source))
                {
                    uniqueSources.Add(source);
                    packageSources.Add(PackageSourceProviderExtensions.ResolveSource(availableSources, source));
                }
            }

            if (packageSources.Count == 0 || config.HasValue())
            {
                packageSources.AddRange(availableSources);
            }

            return(packageSources);
        }