```rust
 let mut data_buffer = [0; 128];
    let mut flash = BlockingAsync::new(unsafe { Rp2040Flash::new() });

    #[no_mangle]
    let data_to_flash = [4];
    embassy_futures::block_on(flash.write(0, &data_to_flash)).unwrap();
    let mut result = [0u8; 1];
    embassy_futures::block_on(flash.read(0, &mut result)).unwrap();
    println!("{}", result);

    let flash_capacity = flash.capacity();
    let retrieved_value: u8 = embassy_futures::block_on(sequential_storage::map::fetch_item(&mut flash, 0..flash_capacity as u32, &mut NoCache::new(), &mut data_buffer, SHOW_LED_KEY)).unwrap().unwrap_or(0);
    let should_light_up = retrieved_value != 0;
```
now repleacted this doesnt work