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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 game_number_for_day(self):
 """ Returns an ``int`` denoting which game is played for the team during the given day. Default value is 1 where a team plays only one game during the day, but can be higher for double headers, etc. For example, if a team has a double header one day, the first game of the day will return 1 while the second game will return 2. """

        game_number = re.findall(r'\(\d+\)', self._date)
        if len(game_number) == 0:
            return 1
        game_number = re.findall(r'\d+', game_number[0])
        return int(game_number[0])