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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_merkle_hash(self):
 """Raise a BadMerkleRootError if the Merkle hash of the transactions does not match the Merkle hash included in the block."""

        calculated_hash = merkle([tx.hash() for tx in self.txs], double_sha256)
        if calculated_hash != self.merkle_root:
            raise BadMerkleRootError(
                "calculated %s but block contains %s" % (b2h(calculated_hash), b2h(self.merkle_root)))