message: deprecate mac_address() since it uses unwrap().  Suggest to use NetworkInterface.mac field instead.
diff: @@ -223,6 +223,10 @@ pub struct NetworkInterface {
  impl NetworkInterface {
  /// Retrieve the MAC address associated with the interface.
  + #[deprecated(
  + since = "0.26.0",
  + note = "Please use NetworkInterface's field 'mac' instead."
  + )]
  pub fn mac_address(&self) -> MacAddr {
  self.mac.unwrap()
  }
  