def METHOD_NAME(b_mock, new_validator, node_key):
    voters = ValidatorElection.recipients(b_mock)
    new_validator['power'] = 30
    election = ValidatorElection.generate([node_key.public_key],
                                          voters,
                                          new_validator, None).sign([node_key.private_key])
    with pytest.raises(InvalidPowerChange):
        election.validate(b_mock)