You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: metrics.rs
    path of file: ./repos/linkerd2-proxy/linkerd/app/inbound/src
    
    the code of the file until where you have to start completion: //! Inbound proxy metrics.
//!
//! While this module is very similar to `outbound::metrics`, it is bound to `inbound_`-prefixed
//! metrics and derives its labels from inbound-specific types. Eventually, we won't rely on the
//! legacy `proxy` met
    
    fn fmt_metrics(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        self.http_authz.fmt_metrics(f)?;
        self.http_errors.fmt_metrics(f)?;

        self.tcp_authz.fmt_metrics(f)?;
        self.tcp_errors.fmt_metrics(f)?;

        // XXX: Proxy metrics are reported elsewhere.

        Ok(())
    }