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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 overtime(self):
 """ Returns an ``int`` of the number of overtimes that were played during the game, or an int constant if the game went to a shootout. """

        if self._overtime.lower() == 'ot':
            return 1
        if self._overtime.lower() == 'so':
            return SHOOTOUT
        if self._overtime == '':
            return 0
        num = re.findall(r'\d+', self._overtime)
        if len(num) > 0:
            return num[0]
        return 0