realm = new Realm({
            path: 'DeviceDB.realm',
            schema: [
                {
                    name: 'Schedule',
                    primaryKey: 'id',
                    properties: {
                        id: 'int',
                        startingTime: 'string',
                        endingTime: 'string'
                    },
                },
                {
                    name: 'user_devices',
                    primaryKey: 'id',
                    properties: {
                        id: 'int',
                        schedules: 'Schedule[]',
                        dev_name: 'string',
                        dev_serial: 'string'
                },
            },
        ],
        });

const devs = realm.objects('user_devices').filtered('id =' + this.state.deviceId);
    const fetched_schedules = devs.schedules;