public void RegisterNext(IExpenseHander next)
{
_next = next;
}
public void RegisterNext(IExpenseHander next)
{
throw new InvalidOperationException("End of chain handler must be the end of chain");
}
public ExpenseHandler(IExpenseApprower approver)
{
_approver = approver;
_next = EndOfChainExpenseHandler.Instance;
}