Bug: Metrics constructor mutates the Configuration object passed to it

Summary

In src/main/java/dev/openfga/sdk/telemetry/Metrics.java:30-32, the Metrics constructor silently mutates the caller's Configuration:

if (this.configuration.getTelemetryConfiguration() == null) {
    this.configuration.telemetryConfiguration(new TelemetryConfiguration());
}

Impact

• Side effect in constructor — Constructors should not modify their inputs.
• Shared Configuration objects are unsafe — If a Configuration is shared across contexts, one path creating Metrics will silently add a TelemetryConfiguration that affects all other users of that object.

Proposed Fix

Instead of mutating the configuration, handle the null case defensively in the methods that read telemetry config. Alternatively, ensure a non-null default TelemetryConfiguration is set during Configuration construction so the null check is never needed.

Related

• PR #290 (telemetry instance sharing fix)

Start by reading src/main/java/dev/openfga/sdk/telemetry/Metrics.java:30-32 and inspect how Configuration and TelemetryConfiguration are constructed. Confirm the chosen fix prevents Metrics from mutating the caller's Configuration while safely handling a null telemetry configuration, and account for the telemetry instance sharing context from PR #290.