return &callback{before: name, processor: p}
}

func (p *processor) After(name string) *callback {
	return &callback{after: name, processor: p}
}

func (p *processor) Match(fc func(*DB) bool) *callback {
	return &callback{match: fc, processor: p}
}

func (p *processor) Register(name string, fn func(*DB)) error {
	return (&callback{processor: p}).Register(name, fn)
}