$sample * @param int $k * @return array{list>,list,list} */ public function nearest(array $sample, int $k) : array; /** * Return all samples, labels, and distances within a given radius of a sample. * * @internal * * @param list $sample * @param float $radius * @return array{list>,list,list} */ public function range(array $sample, float $radius) : array; /** * Remove the root node and its descendants from the tree. * * @internal */ public function destroy() : void; }