jodd-mail/src/main/java/jodd/mail/CommonEmail.java
protected EmailAddress[] valueOrEmptyArray(EmailAddress[] arr) {
		if (arr == null) {
			arr = EmailAddress.EMPTY_ARRAY;
		}
		return arr;
	}
protected EmailAddress[] valueOrEmptyArray(EmailAddress[] arr) {
		if (arr == null) {
			arr = EmailAddress.EMPTY_ARRAY;
		}
		return arr;
	}
---------------------------------------------------------------- helper