<gh_stars>1-10
class Stack:
    def __init__(self):
        self._items = []

    def is_empty(self):
        return not bool(self._items)

    def push(self, item):
        self._items.append(item)

    def pop(self):
        return self._items.pop()

    def peek(self):
        return self._items[-1]

    def size(self):
        return len(self._items)

    @property
    def items(self):
        return self._items

    @items.setter
    def items(self, value):
        raise ValueError("items cannot be set.")

    @items.deleter
    def items(self):
        raise ValueError("items cannot be deleted.")

class Stack:
    def __init__(self):
        self._items = []

    def is_empty(self):
        return not bool(self._items)

    def push(self, item):
        self._items.append(item)

    def pop(self):
        return self._items.pop()

    def peek(self):
        return self._items[-1]

    def size(self):
        return len(self._items)

    @property
    def items(self):
        return self._items

    @items.setter
    def items(self, value):
        raise ValueError("items cannot be set.")

    @items.deleter
    def items(self):
        raise ValueError("items cannot be deleted.")