I am not able to solve this step. any solutions. I am getting following error. 

Challenge Not yet complete... here's what's wrong: 
The getBoats() method isn't working properly. Define getBoats() In the BoatSearchResults Apex controller to accept an optional boatTypeId and return all boats if no boatTypeId is passed, and a filtered list of boats if a boatTypeId is passed.

getting this error

can anyone help me solving the Second step for Lightning Component Framework Specialist super badge.. I struck in that badge.

I am not able to solve this step. any solutions. I am getting following error. 

Challenge Not yet complete... here's what's wrong: 
The getBoats() method isn't working properly. Define getBoats() In the BoatSearchResults Apex controller to accept an optional boatTypeId and return all boats if no boatTypeId is passed, and a filtered list of boats if a boatTypeId is passed.

getting this error

can anyone help me solving the Second step for Lightning Component Framework Specialist super badge.. I struck in that badge.