public function formatDatasets()
    {
        // This little boy was commented because it's not compatible
        // in laravel < 5.4
        //
        // return Collection::make($this->datasets)
        //     ->each
        //     ->matchValues(count($this->labels))
        //     ->map
        //     ->format($this->labels)
        //     ->toJson();

        return Encoder::encode(
            Collection::make($this->datasets)
                ->each(function ($dataset) {
                    $dataset->matchValues(count($this->labels));
                })
                ->map(function ($dataset) {
                    return $dataset->format($this->labels);
                })
                ->toArray()
        );
    }