def calc_witness_merkle_root(self):
    hashes = [ser_uint256(0)]
    for tx in self.vtx[1:]:
        hashes.append(ser_uint256(tx.calc_sha256(True)))
    return self.get_merkle_root(hashes)
def calc_witness_merkle_root(self):
    hashes = [ser_uint256(0)]
    for tx in self.vtx[1:]:
        hashes.append(ser_uint256(tx.calc_sha256(True)))
    return self.get_merkle_root(hashes)