fn get():
    #path(/) -> list:
        service.get_all()

    #path(/id/{uuid}) -> Customer?:
        service.get(uuid)?

    #path(?firstname={fname} | lastname={lname}) -> Customer?:
        if name:
            service.get_by_firstname(fname)?
        else if lastname:
            service.get_by_lastname(lname)?
        else:
            404

fn post(customer: Customer):
    service.add(customer)


fn put(customer: Customer):
    service.update(customer)