Is there a way of appending an object to a list and returning the result in one line in a functional non-imperative way?
How would you do it if also the original list should not be mutated?
Java 8 is allowed.

I already know how to concat two lists in one line. ([Source](https://stackoverflow.com/a/18687790/5755166))

```
List listAB = Stream.concat(listA.stream(), listB.stream()).collect(Collectors.toList());

```

I also know how to make a list out of objects in one line.

```
List listO1 = Collections.singletonList(objectA);
List listO2 = Stream.of(objectA, objectB).collect(Collectors.toList());
List listOO = Arrays.asList(objectA, objectB);

```

Is there anything better than replacing `listB` in the first line with a part of the following lines?