void Main(string argument)
{
    List<Sandbox.ModAPI.Ingame.IMyTerminalBlock> cargoContainers = new List<Sandbox.ModAPI.Ingame.IMyTerminalBlock>();
    GridTerminalSystem.GetBlocksOfType<IMyCargoContainer>(cargoContainers);

    Sandbox.ModAPI.Ingame.IMyTerminalBlock block = null;

    for (int i = 0; i < cargoContainers.Count; i++)
    {
        if (cargoContainers.CustomName == "CargoTest")
        {
            block = cargoContainers;
            break;
        }
    }
    if (block == null)
        return;

    string data = "";
    List<IMyInventoryItem> items = block.GetInventory(0).GetItems();
    foreach (IMyInventoryItem item in items)
    {
        data += item.ItemId + " " + ItemId.Content.TypeId.ToString() + " " + ItemId.Content.SubtypeId.ToString() + "; ";
    }
    block.CustomData = data;
}