presto-main/src/main/java/io/prestosql/Session.java/Session/toString
class Session:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("queryId", queryId)
                .add("transactionId", transactionId)
                .add("user", getUser())
                .add("principal", getIdentity().getPrincipal().orElse(null))
                .add("source", source.orElse(null))
                .add("catalog", catalog.orElse(null))
                .add("schema", schema.orElse(null))
                .add("path", path)
                .add("traceToken", traceToken.orElse(null))
                .add("timeZoneKey", timeZoneKey)
                .add("locale", locale)
                .add("remoteUserAddress", remoteUserAddress.orElse(null))
                .add("userAgent", userAgent.orElse(null))
                .add("clientInfo", clientInfo.orElse(null))
                .add("clientTags", clientTags)
                .add("clientCapabilities", clientCapabilities)
                .add("resourceEstimates", resourceEstimates)
                .add("startTime", startTime)
                .omitNullValues()
                .toString();
    }