There is no need to assign within the callback for a putIfAbsent
default. Refactor to the most idiomatic version today which is to use
??= (since we don't ever assign a null value so we don't care about
the distinction between a missing key and a key assigned to null) and
return the value directly rather than putting it in the Map and then
pulling it back out.
There is no need to assign within the callback for a
putIfAbsentdefault. Refactor to the most idiomatic version today which is to use??=(since we don't ever assign a null value so we don't care about the distinction between a missing key and a key assigned to null) and return the value directly rather than putting it in the Map and then pulling it back out.