@Override
    public Result apply(ApplyNode applyNode, Captures captures, Context context)
    {
        return Result.ofPlanNode(applyNode.getInput());
    }
@Test
    public void testEmptyAssignments()
    {
        tester().assertThat(new RemoveUnreferencedScalarApplyNodes())
                .on(p -> p.apply(
                        Assignments.of(),
                        ImmutableList.of(),
                        p.values(p.variable("x")),
                        p.values(p.variable("y"))))
                .matches(values("x"));
    }