Type: function(array_of_objects, nextToEachOther)
Fired when best available objects are successfully selected. This callback receives two parameters:
array_of_objects: the best available objects
nextToEachOther: boolean that indicates whether the selected seats are next to each other. If they aren't, you could for example show a warning to the ticket buyer.
nextToEachOtheris null when tables or booths are selected instead of seats.