See how to use an extension method in C# to update all items in a list.
public static IEnumerable<T> ForEach<T>(this IEnumerable<T> collection, Action<T> action) { //Loop thru the collection foreach (T item in collection) { action(item); } return collection; }
Example:
californiaClients.ForEach<Client>(timezone => timeZone.value = "PST");