public function up(): void 	{ 		Schema::create('question_answer_groups', function (Blueprint $table): void { 			$table->uuid('id')->primary(); 			$table->uuid('question_id')->nullable(); 			$table->json('title'); 			$table->json('grouped_values');  			$table->timestamps();  			$table->foreign('question_id')->references('id')->on('questions')->nullOnDelete(); 			$table->index(Model::CREATED_AT); 		}); 	}