public static void calculateLastModified(Emails emails) { if (emails != null && emails.getEmails() != null && !emails.getEmails().isEmpty()) { LastModifiedDate latest = null; for (Email email : emails.getEmails()) { if (email.getLastModifiedDate() != null && email.getLastModifiedDate().after(latest)) { latest = email.getLastModifiedDate(); } } emails.setLastModifiedDate(latest); } }