If the employer provides the training, then it is considered work and you should be paid. But the employer could have required you to find your own class and pay for it, and if it did that, it would *not* have to pay for the class or pay for your time, since employers may mandate the education, training, qualifications, etc. that employees need to have their jobs; it's only when the employer chooses to provide the training that it becomes compensatable "work" in the eyes of the law. So while you could try to push the issue and sue your employer for the 4 hours of pay (e.g. in small claims court), you may wish to instead simply consider yourself lucky that your employer is paying for the course rather than making you pay for it yourself.