- add unwrapping
  https://go.dev/blog/go1.13-errors#the-unwrap-method
- add As method, takes a ptr to a slice of []error to return the first matching error type (errors.As) for each?
  - add AsAll [][]error ptr param for multiple errors per type?
  - add Map, returns map[string][]error, where key is k:
	var sb strings.Builder
	t = reflect.TypeOf(err)
	if t.PkgPath() != "" {
		sb.WriteString(t.PkgPath())
	} else {
		sb.WriteString("<UNKNOWN>")
	}
	sb.WriteString(".")
	if t.Name() != "" {
		sb.WriteString(t.Name())
	} else {
		sb.WriteString("<UNKNOWN>")
	}
	k = sb.String()
  - support generics for similar to above?
    - this might allow for "error filtering"