Firebase Docs Reference com.google.firebase.perf.metrics Annotations AddTrace An annotation when applied to a method will create a Trace object with given name and insert start() at the start of the method and stop() at the end. Classes HttpMetric Metric used to collect data for network requests/responses. Trace Trace allows you to set beginning and end of a certain action in your app. Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Last updated December 19, 2017.