def segwit_sighash(self, index, script, prevout_value=None,
                       sighash_type=None, anyone_can_pay=False):
        '''
        this function sets up sighash in BIP143 style
        https://github.com/bitcoin/bips/blob/master/bip-0143.mediawiki
        https://ricette.giallozafferano.it/Spaghetti-alla-Norma.html
        '''
        data = ByteData()

        # 1. nVersion of the transaction (4-byte little endian)
        data += self.version

        # 2. hashPrevouts (32-byte hash)
        data += self._hash_prevouts(anyone_can_pay=anyone_can_pay)

        # 3. hashSequence (32-byte hash)
        data += self._hash_sequence(sighash_type=sighash_type,
                                    anyone_can_pay=anyone_can_pay)

        # 4. outpoint (32-byte hash + 4-byte little endian)
        data += self.tx_ins[index].outpoint

        # 5. scriptCode of the input (serialized as scripts inside CTxOuts)
        data += self._adjusted_script_code(script=script)

        # 6. value of the output spent by this input (8-byte little endian)
        data += prevout_value

        # 7. nSequence of the input (4-byte little endian)
        data += self.tx_ins[index].sequence

        # 8. hashOutputs (32-byte hash)
        data += self._hash_outputs(index=index, sighash_type=sighash_type)

        # 9. nLocktime of the transaction (4-byte little endian)
        data += self.lock_time

        # 10. sighash type of the signature (4-byte little endian)
        data += self._segwit_sighash_adjustment(sighash_type=sighash_type,
                                                anyone_can_pay=anyone_can_pay)

        return utils.hash256(data.to_bytes())
this function sets up sighash in BIP143 style
        https://github.com/bitcoin/bips/blob/master/bip-0143.mediawiki
        https://ricette.giallozafferano.it/Spaghetti-alla-Norma.html