NuGet.PackageDependency.ToString C# (CSharp) Method

        public override string ToString()
        {
            if (VersionSpec == null)
            {
                return Id;
            }

            return Id + " " + VersionUtility.PrettyPrint(VersionSpec);
        }

 internal static void ValidateDependencySets(SemanticVersion version, IEnumerable <PackageDependencySet> dependencies)
 {
     if (version != null)
     {
         using (IEnumerator <PackageDependency> enumerator = (from s in dependencies select s.Dependencies).GetEnumerator())
         {
             while (enumerator.MoveNext())
             {
                 PackageIdValidator.ValidatePackageId(enumerator.Current.Id);
             }
         }
         if (string.IsNullOrEmpty(version.SpecialVersion))
         {
             PackageDependency dependency = Enumerable.FirstOrDefault <PackageDependency>(from set in dependencies select set.Dependencies, new Func <PackageDependency, bool>(PackageBuilder.IsPrereleaseDependency));
             if (dependency != null)
             {
                 object[] args = new object[] { dependency.ToString() };
                 throw new InvalidDataException(string.Format(CultureInfo.CurrentCulture, NuGetResources.Manifest_InvalidPrereleaseDependency, args));
             }
         }
     }
 }