using System;

public class Program

{

    public GroupPrincipal GetWhitelistedGroupPrincipal(string group)

    {

        var whitelistedContextForGroup = new Dictionary<string, PrincipalContext>

        {

            { Config.Groups.DomainUsers, contextUsers },

            { Config.Groups.ManagedGroups, contextUserReflector }

        };

​

        var whitelistedContexts = new List<PrincipalContext>

        {

            contextCompass,

            contextGoogleApps

        };

​

        PrincipalContext context;

        static GroupPrincipal FindGroupPrincipal()

        {

            if (GroupPrincipal.FindByIdentity(context, group) is GroupPrincipal groupPrincipal)

                return groupPrincipal;

​

            return null;

        };

​

        if (whitelistedContextForGroup.ContainsKey(group))

        {

            context = whitelistedContextForGroup[group];

            return FindGroupPrincipal();

        }

​

        foreach (var c in whitelistedContexts)

        {

            context = c;

            return FindGroupPrincipal();

        }

​

        return null;

    }

    public static void Main()

    {

    }

}