pocketmine\inventory\CraftingManager::matchFurnaceRecipe PHP Method

    public function matchFurnaceRecipe(Item $input)
    {
        if (isset($this->furnaceRecipes[$input->getId() . ":" . $input->getDamage()])) {
            return $this->furnaceRecipes[$input->getId() . ":" . $input->getDamage()];
        } elseif (isset($this->furnaceRecipes[$input->getId() . ":?"])) {
            return $this->furnaceRecipes[$input->getId() . ":?"];
        }
        return null;
    }