presto-verifier/src/main/java/io/prestosql/verifier/JsonEventClient.java/JsonEventClient/JsonEventClient
class JsonEventClient:    @Inject
    public JsonEventClient(VerifierConfig config)
            throws FileNotFoundException
    {
        requireNonNull(config.getEventLogFile(), "event log file path is null");
        this.out = new PrintStream(config.getEventLogFile());
    }