format/format.go
func Message(actual interface{}, message string, expected ...interface{}) string {
	if len(expected) == 0 {
		return fmt.Sprintf("Expected\n%s\n%s", Object(actual, 1), message)
	}
	return fmt.Sprintf("Expected\n%s\n%s\n%s", Object(actual, 1), message, Object(expected[0], 1))
}
func Message(actual interface{}, message string, expected ...interface{}) string {
	if len(expected) == 0 {
		return fmt.Sprintf("Expected\n%s\n%s", Object(actual, 1), message)
	}
	return fmt.Sprintf("Expected\n%s\n%s\n%s", Object(actual, 1), message, Object(expected[0], 1))
}
/*
Generates a formatted matcher success/failure message of the form:

	Expected
		<pretty printed actual>
	<message>
		<pretty printed expected>

If expected is omited, then the message looks like:

	Expected
		<pretty printed actual>
	<message>
*/