A savings account object holds a nonnegative balance, and provides deposit (k) and withdraw (k)methods, where deposit (k)add sk to the balance, and withdraw (k) sub tracts k, if the balance is at...

A savings account object holds a nonnegative balance, and provides deposit (k) and withdraw (k)methods, where deposit (k)add sk to the balance, and withdraw (k) sub tracts k, if the balance is at least k, and otherwise blocks until the balance becomes k or greater.