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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 check(self, s, instant_exact=True):
 """Check if a string is in the DB. :param s: str, string to check against the DB. :param instant_exact: bool, look up exact matches with a hash lookup. :return: True or False :rtype: bool """

        all_sets = self._get_comparison_strings(s)
        if instant_exact and s in all_sets:  # exact match
            return True

        for comparison_string in all_sets:
            if self.comparison_func(s, comparison_string) >= self.cutoff:
                return True
        return False