pub trait AuthenticationHandlerExt: AuthenticationHandler {
// Provided methods
fn map_err<TNew, F>(self, f: F) -> MappedAuthenticationHandler<F, Self>
where F: Fn(<Self as AuthenticationHandler>::Error) -> TNew + Send + Sync,
Self: Sized { ... }
fn err_into<TNew>(self) -> MappedErrIntoAuthenticationHandler<Self, TNew>
where Self::Error: Into<TNew>,
Self: Sized { ... }
}