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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 find_broadly_matched_key(self, broad, string):
 """A helper method for matching error strings exactly vs broadly"""

        keys = list(broad.keys())
        for i in range(0, len(keys)):
            key = keys[i]
            if string.find(key) >= 0:
                return key
        return None