I want to collect the values returned by a method called inside a `forEach`:

```
@PostMapping(value="insert-ppl")
public String insertPeople(@RequestBody @Valid @NotNull List<Person> people){
    people.forEach(this::insertPerson);
}

```

the `insertPerson` method returns a string signaling whether the insert in the database was successfull or not. I want to take the strings returned from each call to the `insertPerson`. But I can't use the `.collect` because is not a stream.

How can I do that?