code: def creates(self):
          "returns the address of a contract created by this tx"
          if self.to in (b'', '\0' * 20):
              return mk_contract_address(self.sender, self.noncef creates(self):
          "returns the address of a contract created by this tx"
          if self.to in (b'', '\0' * 20):
              return mk_contract_address(self.sender, self.nonce)
docs: returns the address of a contract created by this tx