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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 ComputeHash(self, key):
 """ Computes the hash of the value passed using MurmurHash3 algorithm. :param bytearray key: Byte array representing the key to be hashed. :return: 32 bit hash value. :rtype: int """

        if key is None:
            raise ValueError("key is None.")

        hash_value = self._ComputeHash(key)
        return bytearray(pack('I', hash_value))