How to use the cryptoconditions.Fulfillment.from_uri function in cryptoconditions

def test_input_deserialization_with_unsigned_fulfillment(ffill_uri, user_pub):
    from bigchaindb.common.transaction import Input
    from cryptoconditions import Fulfillment

    expected = Input(Fulfillment.from_uri(ffill_uri), [user_pub])
    ffill = {
        'owners_before': [user_pub],
        'fulfillment': Fulfillment.from_uri(ffill_uri),
        'fulfills': None,
    }
    input = Input.from_dict(ffill)

    assert input == expected

def test_fulfill_transaction(alice_transaction, alice_sk):
    from bigchaindb_driver.offchain import fulfill_transaction
    fulfilled_transaction = fulfill_transaction(
        alice_transaction, private_keys=alice_sk)
    inputs = fulfilled_transaction['inputs']
    assert len(inputs) == 1
    alice_transaction['inputs'][0]['fulfillment'] = None
    message = rapidjson.dumps(
        alice_transaction,
        skipkeys=False,
        ensure_ascii=False,
        sort_keys=True,
    )
    message = sha3_256(message.encode())
    fulfillment_uri = inputs[0]['fulfillment']
    assert Fulfillment.from_uri(fulfillment_uri).\
        validate(message=message.digest())

Optionally, this method can also serialize a Cryptoconditions-
                Fulfillment that is not yet signed.

            Args:
                data (dict): The Input to be transformed.

            Returns:
                :class:`~bigchaindb.common.transaction.Input`

            Raises:
                InvalidSignature: If an Input's URI couldn't be parsed.
        """
        fulfillment = data['fulfillment']
        if not isinstance(fulfillment, (Fulfillment, type(None))):
            try:
                fulfillment = Fulfillment.from_uri(data['fulfillment'])
            except ASN1DecodeError:
                # TODO Remove as it is legacy code, and simply fall back on
                # ASN1DecodeError
                raise InvalidSignature("Fulfillment URI couldn't been parsed")
            except TypeError:
                # NOTE: See comment about this special case in
                #       `Input.to_dict`
                fulfillment = _fulfillment_from_details(data['fulfillment'])
        fulfills = TransactionLink.from_dict(data['fulfills'])
        return cls(fulfillment, data['owners_before'], fulfills)