public function filterWithKey( callable $callback, ): ImmMap<Tk,Tv>
Only keys and values that meet a certain criteria are affected by a call to
filterWithKey(), while all values are affected by a call to
callable $callback- The callback containing the condition to apply to the current
ImmMapkeys and values.
ImmMapcontaining the values after a user-specified condition is applied to the keys and values of the current
Map::filterWithKey for usage examples.