prow/pjutil/pjutil.go
func NewPresubmit(pr github.PullRequest, baseSHA string, job config.Presubmit, eventGUID string) prowapi.ProwJob {
	refs := createRefs(pr, baseSHA)
	labels := make(map[string]string)
	for k, v := range job.Labels {
		labels[k] = v
	}
	labels[github.EventGUID] = eventGUID
	return NewProwJob(PresubmitSpec(job, refs), labels)
}
func NewPresubmit(pr github.PullRequest, baseSHA string, job config.Presubmit, eventGUID string) prowapi.ProwJob {
	refs := createRefs(pr, baseSHA)
	labels := make(map[string]string)
	for k, v := range job.Labels {
		labels[k] = v
	}
	labels[github.EventGUID] = eventGUID
	return NewProwJob(PresubmitSpec(job, refs), labels)
}
// NewPresubmit converts a config.Presubmit into a prowapi.ProwJob.
// The prowapi.Refs are configured correctly per the pr, baseSHA.
// The eventGUID becomes a github.EventGUID label.