The file m$269\_$tyre$\_$shop.py implements the tyre shop dictionary as a class, TyreShop, and adds the following methods:

add$\_$stack $($to add a given stack name to the dictionary$)$

add$\_$tyre $($to add a given tyre diameter to a given stack name if possible and return success or failure$)$

remove$\_$tyre $($to remove the top tyre from a given stack name, returning the diameter of the tyre removed$)$

check$\_$tyre $($to return the diameter of the top tyre of the stack with the given stack, without removing it from the stack$)$

is$\_$empty $($to return a Boolean indicating whether a stack is empty or not$)$

top$\_$tyres $($returns a dictionary of stack names mapped to the top tyre diameters$)$

get$\_$stack$\_$height $($returns an integer height of a given stack name$)$

show $($a helper method to print out a visible representation of the stacks. This may help you in debugging!$)$

Jo is now considering the process of searching for existing tyres in the stacks.

As Jo always tries to put tyres on the most suitable stack, they assume that the tyre they are searching for is most likely to be in the stack$($s$)$ with the closest diameter top tyre, as long as that diameter is either equal to or smaller than the tyre being searched for.