@Override
    public String toString() {
        return "TopicAssignment" +
            "(assignments=" + assignments +
            ")";
    }
@Test
    public void testToString() {
        List<Integer> replicas = Arrays.asList(0, 1, 2);
        List<Uuid> directories = Arrays.asList(
                Uuid.fromString("v56qeYzNRrqNtXsxzcReog"),
                Uuid.fromString("MvUIAsOiRlSePeiBHdZrSQ"),
                Uuid.fromString("jUqCchHtTHqMxeVv4dw1RA")
        );
        List<PartitionAssignment> partitionAssignments = Collections.singletonList(
            new PartitionAssignment(replicas, directories::get)
        );
        TopicAssignment topicAssignment = new TopicAssignment(partitionAssignments);
        assertEquals("TopicAssignment(assignments=[PartitionAssignment(replicas=[0, 1, 2], " +
                "directories=[v56qeYzNRrqNtXsxzcReog, MvUIAsOiRlSePeiBHdZrSQ, jUqCchHtTHqMxeVv4dw1RA])])", topicAssignment.toString());
    }