Get SData Group Results

/* USINGS
using Saleslogix.SData.Client;
using Saleslogix.SData.Client.Linq;
*/

var groupPluginId = "p6UJ9A00050Q";

var client = new SDataClient("http://localhost/sdata/slx/system/-/")
{
    UserName = "Admin",
    Password = ""
};

var contacts = client.Query("groups(\"" + groupPluginId + "\")/$queries/execute");
foreach (SDataResource contact in contacts)
{
    var contactId = contact["CONTACTID"]?.ToString();
    var email = contact["EMAIL"]?.ToString();
    //...
}