Entry<Optional<ConsumerGroupState>, Optional<Collection<PartitionAssignmentState>>> collectGroupOffsets(String groupId) throws Exception {
            return collectGroupsOffsets(Collections.singletonList(groupId)).getOrDefault(groupId, new SimpleImmutableEntry<>(Optional.empty(), Optional.empty()));
        }
Returns the state of the specified consumer group and partition assignment states
tools/src/main/java/org/apache/kafka/tools/consumer/group/ConsumerGroupCommand.java