presto-main/src/main/java/io/prestosql/FullConnectorSession.java/FullConnectorSession/toString
class FullConnectorSession:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("queryId", getQueryId())
                .add("user", getUser())
                .add("source", getSource().orElse(null))
                .add("traceToken", getTraceToken().orElse(null))
                .add("timeZoneKey", getTimeZoneKey())
                .add("locale", getLocale())
                .add("startTime", getStartTime())
                .add("properties", properties)
                .omitNullValues()
                .toString();
    }