@Test
void removeVehicle() {

    final long vehicleId = 8;
    final Vehicle vehicle = VehicleFactory.testVehicle(vehicleId);
    when(vehicleRepository.removeVehicle(vehicleId)).thenReturn(vehicle);
    vehicleService.removeVehicle(vehicleId);
    verify(vehicleRepository).removeVehicle(vehicleId);
    verify(optimizer).removeVehicle(vehicle);
}