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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 unmarshall_key(self, key):
 """ Unmarshalls a Crash key read from the database. @type key: str or buffer @param key: Key to convert. @rtype: L{Crash} key. @return: Converted key. """

        key = str(key)
        if self.escapeKeys:
            key = key.decode('hex')
        if self.compressKeys:
            key = zlib.decompress(key)
        key = pickle.loads(key)
        return key