prow/config/jobs.go
func (c *JobConfig) SetPresubmits(jobs map[string][]Presubmit) error {
	nj := map[string][]Presubmit{}
	for k, v := range jobs {
		nj[k] = make([]Presubmit, len(v))
		copy(nj[k], v)
		if err := SetPresubmitRegexes(nj[k]); err != nil {
			return err
		}
	}
	c.Presubmits = nj
	return nil
}
func (c *JobConfig) SetPresubmits(jobs map[string][]Presubmit) error {
	nj := map[string][]Presubmit{}
	for k, v := range jobs {
		nj[k] = make([]Presubmit, len(v))
		copy(nj[k], v)
		if err := SetPresubmitRegexes(nj[k]); err != nil {
			return err
		}
	}
	c.Presubmits = nj
	return nil
}
// SetPresubmits updates c.Presubmits to jobs, after compiling and validating their regexes.