Add a boolean instance variable to GreenhouseControls called $$fans$.$ Create two Event classes called FansOn and FansOff. The action$()$ of these two classes should modify fan to true or false respectively.

$2.$ Modify Bell Event so that it will be able to run an arbitrary number of times separated by $2000$ msec each. To facilitate this requirement, you should generate the number of Bell Events specified in the rings parameter in the examples file. Please pay special attention to the possibility that other events might be run in between the various Bell events.