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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 search(self, buf):
 """Search the provided buffer for a match to any sub-searchers. Search the provided buffer for a match to any of this collection's sub-searchers. If a single matching sub-searcher is found, returns that sub-searcher's *match* object. If multiple matches are found, the match with the smallest index is returned. If no matches are found, returns ``None``. :param buf: Buffer to search for a match. :return: :class:`RegexMatch` if matched, None if no match was found. """

        self._check_type(buf)
        best_match = None
        best_index = sys.maxsize
        for searcher in self:
            match = searcher.search(buf)
            if match and match.start < best_index:
                best_match = match
                best_index = match.start
        return best_match