job := engine.NewJob(func() { // do something }) err := job.Run() if err != nil { return nil, job.JobErrorf("error occurred while executing job: %s", err.Error()) }In this example, `JobErrorf` is used to create an error if the `job.Run()` returns an error. It provides an error message that includes the original error message. Overall, the `JobErrorf` function is used to handle errors that occur during the execution of a Docker job. It is part of the docker engine package in Go.