middleware/content_charset.go
func split(str, sep string) (string, string) {
	var a, b string
	var parts = strings.SplitN(str, sep, 2)
	a = strings.TrimSpace(parts[0])
	if len(parts) == 2 {
		b = strings.TrimSpace(parts[1])
	}

	return a, b
}
func split(str, sep string) (string, string) {
	var a, b string
	var parts = strings.SplitN(str, sep, 2)
	a = strings.TrimSpace(parts[0])
	if len(parts) == 2 {
		b = strings.TrimSpace(parts[1])
	}

	return a, b
}
// Split a string in two parts, cleaning any whitespace.