protected function features() : array
	{
		$features = $this->products->pluck('features');

		return Collection::make($this->allowed)->mapWithKeys(function ($allowed) use ($features) {

			return [
				$allowed => $features->pluck($allowed)->filter(function ($allowed) {
					return ! is_null($allowed);
				})->all()
			];

		})->all();
	}