Can the Spark be put to sleep while waiting for a request for data from the server?

Can the Spark be put to sleep while waiting for a request for data from the server?

The Spark Core and the Photon need to be awake to receive wifi data, so they cannot be put to sleep while waiting for a request to return.

Requests/responses typically last only a few seconds, so there would be relatively little energy to save by sleeping for that length of time. It would be better to sleep after receiving the response.