// //! This example is part unit test and part demonstration.
// //!
// //! We show all of the registration macros, as well as all of the "emission" macros, the ones you
// //! would actually call to update a metric.
// //!
// //! We demonstrate the various permutations of values that can be passed in the macro calls, all of
// //! which are documented in detail for the respective macro.
// use metrics::{
//     counter, decrement_gauge, gauge, histogram, increment_counter, increment_gauge,
//     register_counter, register_gauge, register_histogram, GaugeValue, Key, Recorder, Unit,
// };

// #[derive(Default)]
// struct PrintRecorder;

// impl Recorder for PrintRecorder {
//     fn register_counter(&self, key: &Key, unit: Option<Unit>, description: Option<&'static str>) {
//         println!(
//             "(counter) registered key {} with unit {:?} and description {:?}",
//             key, unit, description
//         );
//     }

//     fn register_gauge(&self, key: &Key, unit: Option<Unit>, description: Option<&'static str>) {
//         println!(
//             "(gauge) registered key {} with unit {:?} and description {:?}",
//             key, unit, description
//         );
//     }

//     fn register_histogram(&self, key: &Key, unit: Option<Unit>, description: Option<&'static str>) {
//         println!(
//             "(histogram) registered key {} with unit {:?} and description {:?}",
//             key, unit, description
//         );
//     }

//     fn increment_counter(&self, key: &Key, value: u64) {
//         println!("(counter) got value {} for key {}", value, key);
//     }

//     fn update_gauge(&self, key: &Key, value: GaugeValue) {
//         println!("(gauge) got value {:?} for key {}", value, key);
//     }

//     fn record_histogram(&self, key: &Key, value: f64) {
//         println!("(histogram) got value {} for key {}", value, key);
//     }
// }

// fn init_print_logger() {
//     let recorder = PrintRecorder::default();
//     metrics::set_boxed_recorder(Box::new(recorder)).unwrap()
// }

// #[test]
// fn main_test() {
//     let server_name = "web03".to_string();

//     init_print_logger();

//     let common_labels = &[("listener", "frontend")];

//     // Go through registration:
//     register_counter!("requests_processed", "number of requests processed");
//     register_counter!("bytes_sent", Unit::Bytes);
//     register_gauge!("connection_count", common_labels);
//     register_histogram!(
//         "svc.execution_time",
//         Unit::Milliseconds,
//         "execution time of request handler"
//     );
//     register_gauge!("unused_gauge", "service" => "backend");
//     register_histogram!("unused_histogram", Unit::Seconds, "unused histo", "service" => "middleware");

//     // All the supported permutations of `increment!`:
//     counter!("requests_processed").increment(1);
//     counter!("requests_processed", "request_type" => "admin").increment(1);
//     counter!("requests_processed", "request_type" => "admin", "server" => server_name.clone()).increment(1);
//     counter!("requests_processed", common_labels).increment(1);

//     // All the supported permutations of `counter!`:
//     counter!("bytes_sent", 64);
//     counter!("bytes_sent", 64, "listener" => "frontend");
//     counter!("bytes_sent", 64, "listener" => "frontend", "server" => server_name.clone());
//     counter!("bytes_sent", 64, common_labels);

//     // All the supported permutations of `gauge!` and its increment/decrement versions:
//     gauge!("connection_count", 300.0);
//     gauge!("connection_count", 300.0, "listener" => "frontend");
//     gauge!("connection_count", 300.0, "listener" => "frontend", "server" => server_name.clone());
//     gauge!("connection_count", 300.0, common_labels);
//     increment_gauge!("connection_count", 300.0);
//     increment_gauge!("connection_count", 300.0, "listener" => "frontend");
//     increment_gauge!("connection_count", 300.0, "listener" => "frontend", "server" => server_name.clone());
//     increment_gauge!("connection_count", 300.0, common_labels);
//     decrement_gauge!("connection_count", 300.0);
//     decrement_gauge!("connection_count", 300.0, "listener" => "frontend");
//     decrement_gauge!("connection_count", 300.0, "listener" => "frontend", "server" => server_name.clone());
//     decrement_gauge!("connection_count", 300.0, common_labels);

//     // All the supported permutations of `histogram!`:
//     histogram!("svc.execution_time", 70.0);
//     histogram!("svc.execution_time", 70.0, "type" => "users");
//     histogram!("svc.execution_time", 70.0, "type" => "users", "server" => server_name.clone());
//     histogram!("svc.execution_time", 70.0, common_labels);
// }