public EventHubsSystemDescriptor withSendKeys(boolean sendKeys) {
    this.producerEventhubsSendKey = Optional.of(sendKeys);
    return this;
  }
If set to true, the key of the Samza message will be included as the 'key' property in the outgoing EventData
 message for Event Hubs. The Samza message key will not be sent otherwise.
 Note: If the Samza Event Hubs consumer is used, this field is the partition key of the received EventData, or the
 message key if the partition key is not present.

@param sendKeys set to true if the message key should be sent in the EventData properties, the key is not sent otherwise
@return this system descriptor
samza-azure/src/main/java/org/apache/samza/system/eventhub/descriptors/EventHubsSystemDescriptor.java