public void ManagerHasNoPending()
{
//arrange
FuelManager manager = new FuelManager();
FuelTank tank = new FuelTank("Unl", 1000);
FuelReceipt reciept = new FuelReceipt(tank, 100);
manager.Commands.Add(reciept);
//act
manager.ExecuteCommands();
//assert
Assert.AreEqual(false, manager.HasPendingCommands());
}
