Documentation code does not work properly

[huifer]

link : https://embassy.dev/book/#_pac_version
Code source : https://github.com/embassy-rs/embassy/blob/main/docs/examples/layer-by-layer/blinky-pac/src/main.rs

#![no_std]
#![no_main]

use pac::gpio::vals;
use {defmt_rtt as _, panic_probe as _, stm32_metapac as pac};

#[cortex_m_rt::entry]
fn main() -> ! {
    // Enable GPIO clock
    let rcc = pac::RCC;
    rcc.ahb2enr().modify(|w| {
        w.set_gpioben(true);
        w.set_gpiocen(true);
    });

    rcc.ahb2rstr().modify(|w| {
        w.set_gpiobrst(true);
        w.set_gpiocrst(true);
        w.set_gpiobrst(false);
        w.set_gpiocrst(false);
    });

    // Setup button
    let gpioc = pac::GPIOC;
    const BUTTON_PIN: usize = 13;
    gpioc.pupdr().modify(|w| w.set_pupdr(BUTTON_PIN, vals::Pupdr::PULL_UP));
    gpioc.otyper().modify(|w| w.set_ot(BUTTON_PIN, vals::Ot::PUSH_PULL));
    gpioc.moder().modify(|w| w.set_moder(BUTTON_PIN, vals::Moder::INPUT));

    // Setup LED
    let gpiob = pac::GPIOB;
    const LED_PIN: usize = 14;
    gpiob.pupdr().modify(|w| w.set_pupdr(LED_PIN, vals::Pupdr::FLOATING));
    gpiob.otyper().modify(|w| w.set_ot(LED_PIN, vals::Ot::PUSH_PULL));
    gpiob.moder().modify(|w| w.set_moder(LED_PIN, vals::Moder::OUTPUT));

    // Main loop
    loop {
        if gpioc.idr().read().idr(BUTTON_PIN) == vals::Idr::LOW {
            gpiob.bsrr().write(|w| w.set_bs(LED_PIN, true));
        } else {
            gpiob.bsrr().write(|w| w.set_br(LED_PIN, true));
        }
    }
}

In the above code, use pac:gpio::vals; Is there any other way to pour Vals properly.

cargo.toml ：

# This file was automatically generated.

[package]
edition = "2021"
name = "app"
version = "0.1.0"

[dependencies]
embassy-stm32 = { version = "0.2.0", features =  ["defmt",
    "stm32l431rc", "time-driver-any", "memory-x", "unstable-pac", "exti", "chrono","low-power"]  }
embassy-executor = { version = "0.7.0", features = ["nightly", "arch-cortex-m", "executor-thread", "defmt"] }
embassy-time = { version = "0.4.0", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
ufmt = "0.1"
embassy-futures = {version = "0.1.1",features = ["defmt"]}
defmt = "0.3.5"
defmt-rtt = "0.4.0"
cortex-m = {version = "0.7.7", features = ["critical-section-single-core"]}
cortex-m-rt = "0.7.3"
panic-probe = "0.3.1"

embedded-io-async = "0.6.1"
embedded-io = "0.6.1"
embedded-alloc = {version = "=0.6.0", features = ["llff"]}
heapless="0.8.0"
nb = "1.0.0"
static_cell = "2"
stm32-metapac = {version = "16.0.0",features = ["pac","stm32l431rc"]}
embassy-sync = "0.6.2"
[[bin]]
name = "app"
test = false
bench = false

[profile.dev]


[profile.release]
debug = true
[features]
default = ["defmt-default"]
defmt-default = []
defmt-trace = []
defmt-debug = []
defmt-info = []
defmt-warn = []
defmt-error = []