def aunset_user(uid, optional)
      optional.key?('properties') ||
        fail(ArgumentError, 'properties must be present when event is $unset')
      optional['properties'].empty? &&
        fail(ArgumentError, 'properties cannot be empty when event is $unset')
      acreate_event('$unset', 'user', uid, optional)
    end
def aunset_user(uid, optional)
      optional.key?('properties') ||
        fail(ArgumentError, 'properties must be present when event is $unset')
      optional['properties'].empty? &&
        fail(ArgumentError, 'properties cannot be empty when event is $unset')
      acreate_event('$unset', 'user', uid, optional)
    end
:category: Asynchronous Methods
 Asynchronously request to unset properties of a user and return a
 PredictionIO::AsyncResponse object immediately.

 properties must be a non-empty Hash.

 Corresponding REST API method: POST /events.json

 See also #unset_user.