@Override
  public Map<String, String> toConfig() {
    Map<String, String> ehConfigs = new HashMap<>(super.toConfig());

    String streamId = getStreamId();

    ehConfigs.put(String.format(EventHubConfig.CONFIG_STREAM_NAMESPACE, streamId), namespace);
    ehConfigs.put(String.format(EventHubConfig.CONFIG_STREAM_ENTITYPATH, streamId), entityPath);

    sasKeyName.ifPresent(keyName ->
        ehConfigs.put(String.format(EventHubConfig.CONFIG_STREAM_SAS_KEY_NAME, streamId), keyName));
    sasToken.ifPresent(key ->
        ehConfigs.put(String.format(EventHubConfig.CONFIG_STREAM_SAS_TOKEN, streamId), key));
    consumerGroup.ifPresent(consumerGroupName ->
        ehConfigs.put(String.format(EventHubConfig.CONFIG_STREAM_CONSUMER_GROUP, streamId), consumerGroupName));
    return ehConfigs;
  }
Set the consumer group from the upstream Event Hubs entity that the consumer is part of. Defaults to the
<code>$Default</code> group that is initially present in all Event Hubs entities (unless removed)

@param consumerGroup the name of the consumer group upstream
@return this input descriptor
samza-azure/src/main/java/org/apache/samza/system/eventhub/descriptors/EventHubsInputDescriptor.java