Stack := Object clone do(
    newSlot("stack")
    newSlot("capacity", 10)

    init := method(stack = list)

    push := method(x,
        if(stack size + 1 > capacity,
            StackOverflowError raise("Stack is full.")
        )
        stack push(x)
    )

    top := method(
        if(stack size == 0,
            StackUnderflowError raise("Cannot call top on an empty stack.")
        )
        stack last
    )

    pop := method(
        if(stack size == 0,
            StackUnderflowError raise("Cannot call pop on an empty stack.")
        )
        stack removeLast
    )
)