Sets the overlay override value of this task
Values you give are 0 to 15, indicating the white overlay and the damage overlay levels you want to use
Passing nil will reset the overlay override for this task
  overload 1:
                        
BlockTask:setOverlay(overlay)  
  | Method Property | Fluent Description | Representation | 
|---|
 | overlay accepts | a Vector2 |  | 
| Return Value | nil |  | 
 
  overload 2:
                        
BlockTask:setOverlay(whiteOverlay, hurtOverlay)  
  | Method Property | Fluent Description | Representation | 
|---|
 | whiteOverlay accepts | an Integer |  | 
| hurtOverlay accepts | an Integer |  | 
| Return Value | nil |  |