private static String toString(Suite suite) {
        if (suite == null) return "Tests";
        switch (suite) {
            case SYSTEM_TEST: return "System test";
            case STAGING_SETUP_TEST: return "Staging setup";
            case STAGING_TEST: return "Staging test";
            case PRODUCTION_TEST: return "Production test";
            default: throw new IllegalArgumentException("unexpected suite '" + suite + "'");
        }
    }
Recursively trims stack traces for the given throwable and its causes/suppressed.
This is based on the assumption that the relevant stack is anything above the first native
reflection invocation, above any frame in the given root class.
vespa-osgi-testrunner/src/main/java/com/yahoo/vespa/testrunner/TestReport.java