laravel unique multiple columns

'mobile_no' 
  => 'unique:users,mobile_no,NULL,id,country_id,'.request('country_id');

$table->unique(['mytext', 'user_id']);

    public function up()
    {
        Schema::table('user_projects', function (Blueprint $table) {
            $table->unique(["user_id", "project_id"], 'user_project_unique');
        });
    }

    public function down()
    {
        Schema::table('user_projects', function (Blueprint $table) {
          $table->dropUnique('user_project_unique');
        });
    }