def __init__(self, value: T, parent: Optional[Any]=None, callback: Optional[Callable[([], None)]]=None):
    ' Initialize the PageProperty to always have value v.'
    self._values: List[Tuple[(int, T)]] = [(0, value)]
    self.set_parent(parent)
    self._callback = callback
Initialize the PageProperty to always have value v.
def __init__(self, value: T, parent: Optional[Any]=None, callback: Optional[Callable[([], None)]]=None):
    ' '
    self._values: List[Tuple[(int, T)]] = [(0, value)]
    self.set_parent(parent)
    self._callback = callback