/// <summary>Commit a Contact Id in the contact's collection of Ids.</summary>
 /// <param name="contact">The contact that is having this Contact Id committed.</param>
 /// <param name="arrayNode">The array node where this Contact Id is being committed.</param>
 /// <param name="value">The Contact Id being committed.</param>
 private static void _CommitContactId(Contact contact, string arrayNode, Guid? value)
 {
     Assert.IsTrue(arrayNode.StartsWith(PropertyNames.ContactIdCollection + PropertyNames.ContactIdArrayNode, StringComparison.Ordinal));
     if (null != value)
     {
         contact.SetStringProperty(arrayNode + PropertyNames.Value, value.ToString());
     }
     else
     {
         contact.RemoveProperty(arrayNode + PropertyNames.Value);
     }
 }