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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 getsatstars(self, verbose = None):
 """ Returns the mask of saturated stars after finding them if not yet done. Intended mainly for external use. """

        if verbose == None:
            verbose = self.verbose
        if not self.satlevel > 0:
            raise RuntimeError, "Cannot determine satstars : you gave satlevel <= 0 !" 
        if self.satstars == None:
            self.findsatstars(verbose = verbose)
        return self.satstars