56-duplicate-contacts

public Boolean duplicateContacts(Contact c1, Contact c2) {
    //code here
    if(!String.isBlank(c1.phone) && !String.isBlank(c2.phone) && c1.phone == c2.phone)
        return true;
    if(!String.isBlank(c1.email) && !String.isBlank(c2.email) && c1.email == c2.email)
        return true;
    return false;
}