func A(m Model, field string) string {
	// find field
	f := Init(m).Meta().Fields[field]
	if f == nil {
		panic(fmt.Sprintf(`coal: field "%s" not found on "%s"`, field, m.Meta().Name))
	}

	return f.JSONKey
}
func A(m Model, field string) string {
	// find field
	f := Init(m).Meta().Fields[field]
	if f == nil {
		panic(fmt.Sprintf(`coal: field "%s" not found on "%s"`, field, m.Meta().Name))
	}

	return f.JSONKey
}
// A is a short-hand function to extract the attribute JSON key of a model field.
//
// Note: A will panic if no field has been found.