public SortedDictionary <string, SourceFile> GetSourceFiles()
{
return(new SortedDictionary <string, SourceFile>(Assemblies
.SelectMany(a => a.SourceFiles)
.GroupBy(kv => kv.Key, kv => kv.Value)
.ToDictionary(g => g.Key, g => SourceFile.Merge(g))));
}