C#: Address review comments.

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/FeedManager.cs

@@ -90,7 +90,7 @@ private IEnumerable<string> GetFeedsFromNugetConfig(string nugetConfigPath) =>
 
         public string FeedsToRestoreArgument(IEnumerable<string> feeds, string sourceArgumentPrefix)
         {
-            // If there are no feeds, we want to override any default feeds that `dotnet restore` would use by passing a dummy source argument.
+            // If there are no feeds, we want to override any default feeds that `restore` would use by passing a dummy source argument.
             if (!feeds.Any())
             {
                 return $" {sourceArgumentPrefix} \"{emptyPackageDirectory.DirInfo.FullName}\"";
@@ -112,7 +112,7 @@ public string FeedsToRestoreArgument(IEnumerable<string> feeds, string sourceArg
         /// (1) Use the feeds we get from `dotnet nuget list source`
         /// (2) Use private registries, if they are configured
         /// </summary>
-        /// <param name="path">Path to project/solution</param>
+        /// <param name="path">Path to project/solution/packages.config</param>
         /// <param name="reachableFeeds">The set of reachable NuGet feeds.</param>
         /// <returns>The list of NuGet feeds to use for this restore.</returns>
         public IEnumerable<string> FeedsToUse(string path, HashSet<string> reachableFeeds)

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/PackagesConfigRestorer.cs

@@ -72,8 +72,6 @@ private class NugetExeWrapper : IPackagesConfigRestore
             private bool IsDefaultFeedReachable =>
                 isDefaultFeedReachable ??= feedManager.IsDefaultFeedReachable();
 
-
-
             /// <summary>
             /// Create the package manager for a specified source tree.
             /// </summary>
@@ -175,7 +173,8 @@ private bool TryRestoreNugetPackage(string packagesConfig)
                 var feedsToUse = feedManager.FeedsToUse(packagesConfig, reachableFeeds).ToList();
                 var useDefaultFeed = feedsToUse.Count == 0 && IsDefaultFeedReachable;
 
-                // Explicitly construct the sources to be used for the restore command if any of the following is true:
+                // Explicitly construct the sources to be used for the restore command when checking feed
+                // responsiveness, using private registries, or falling back to nuget.org.
                 if (feedManager.CheckNugetFeedResponsiveness || feedManager.HasPrivateRegistryFeeds || useDefaultFeed)
                 {
                     if (useDefaultFeed)