public PackageReferenceFileList(Solution solution)
        {
            _projectPackageReferenceFiles = new List <ProjectPackageReferenceFile>();

            var packageReferenceFileName = Path.Combine(
                VsUtility.GetNuGetSolutionFolder(solution),
                VsUtility.PackageReferenceFile);

            if (File.Exists(packageReferenceFileName))
            {
                _solutionPackageReferenceFile = packageReferenceFileName;
            }

            foreach (Project project in solution.Projects)
            {
                GetPackageReferenceFiles(project);
            }
        }
        /// <summary>
        /// Returns true if the solution is using the old style package restore.
        /// </summary>
        /// <param name="solution">The solution to check.</param>
        /// <returns>True if the solution is using the old style package restore.</returns>
        private static bool UsingOldPackageRestore(Solution solution)
        {
            var nugetSolutionFolder = VsUtility.GetNuGetSolutionFolder(solution);

            return(File.Exists(Path.Combine(nugetSolutionFolder, "nuget.targets")));
        }