Which expression calls build_profile only when user_id is absent?

Which expression calls build_profile only when user_id is absent?

1. profiles.entry(user_id).or_insert_with(build_profile)
2. profiles.entry(user_id).or_insert(build_profile())
3. profiles.get(&user_id).unwrap_or(&build_profile())
4. profiles.contains_key(&user_id).then(build_profile)