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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def center_widget_on_screen(widget, screen=None):
 """ Centers given Widget on the screen. :param widget: Current Widget. :type widget: QWidget :param screen: Screen used for centering. :type screen: int :return: Definition success. :rtype: bool """


    screen = screen and screen or QApplication.desktop().primaryScreen()
    desktop_width = QApplication.desktop().screenGeometry(screen).width()
    desktop_height = QApplication.desktop().screenGeometry(screen).height()
    widget.move(desktop_width / 2 - widget.sizeHint().width() / 2, desktop_height / 2 - widget.sizeHint().height() / 2)
    return True