fn as_slice(&self) -> &[u8] {
        match self {
            Key::Key16(key) => key,
            #[cfg(any(esp32, esp32s2))]
            Key::Key24(key) => key,
            Key::Key32(key) => key,
        }
    }
Returns a slice representation of the AES key.
esp-hal/src/aes/mod.rs