qrcode = "0.13.0"
image = "0.25.0"

    // Encode some data into bits.
    let code = QrCode::new(b"01234567").unwrap();

    // Render the bits into an image.
    let image = code.render::<Luma<u8>>().build();

    // Save the image.
    image.save("/tmp/qrcode.png").unwrap();

error[E0277]: the trait bound `Luma<u8>: Element` is not satisfied
   --> src/main.rs:44:31
    |
44  |     let image = code.render::<Luma<u8>>().build();
    |                      ------   ^^^^^^^^ the trait `Element` is not implemented for `Luma<u8>`
    |                      |
    |                      required by a bound introduced by this call
    |
    = help: the following other types implement trait `Element`:
              char
              &'a str
    = note: required for `Luma<u8>` to implement `qrcode::render::Pixel`
note: required by a bound in `QrCode::render`
   --> /Users/aya/.cargo/registry/src/rsproxy.cn-8f6827c7555bfaf8/qrcode-0.13.0/src/lib.rs:249:22
    |
249 |     pub fn render<P: Pixel>(&self) -> Renderer<P> {
    |                      ^^^^^ required by this bound in `QrCode::render`