@Override
    public VertexParallelismInformation getParallelismInfo(JobVertexID vertexId) {
        return Optional.ofNullable(vertexToParallelismInfo.get(vertexId))
                .orElseThrow(
                        () ->
                                new IllegalStateException(
                                        String.format(
                                                "No parallelism information set for vertex %s",
                                                vertexId)));
    }
@Test
    void testNotSet() {
        DefaultVertexParallelismStore store = new DefaultVertexParallelismStore();

        assertThatThrownBy(() -> store.getParallelismInfo(new JobVertexID()))
                .withFailMessage("No parallelism information set for vertex")
                .isInstanceOf(IllegalStateException.class);
    }