public Set<TopicPartition> assignment() {
        return delegate.assignment();
    }
Get the set of partitions currently assigned to this consumer. If subscription happened by directly assigning
partitions using {@link #assign(Collection)} then this will simply return the same partitions that
were assigned. If topic subscription was used, then this will give the set of topic partitions currently assigned
to the consumer (which may be none if the assignment hasn't happened yet, or the partitions are in the
process of getting reassigned).
@return The set of partitions currently assigned to this consumer
clients/src/main/java/org/apache/kafka/clients/consumer/KafkaConsumer.java