metrics property
Metrics is a live sample, and sending one IS A HEARTBEAT: it refreshes the row and starts the 90-second liveness window, and it is appended to the fleet series as one point. Its own at is ignored — the server stamps the time, so a client can never age or backdate its own machine. Omit it to register a machine without claiming it is alive.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
Metrics? metrics;