Currently only supports USB client side (via nusb)
Printing fastboot using the nusb:
```rust,no_run
async fn main() -> anyhow::Result<()> {
let mut devices = fastboot_protocol::nusb::devices()?;
let info = devices.next()
let mut fb = fastboot_protocol::nusb::NusbFastBoot::from_info(&info)?;
println!("Fastboot version: {}", fb.get_var("version").await?);
Ok(())
}
```