Monolog: brackets added at the end of each log [duplicate]

This question already has an answer here:

• How not to show last bracket in a monolog log line? 2 answers

I'm using Monolog in Laravel 5.1 and wondering what these brackets that get added are.

I'm doing:

$log = new Logger('local');
$log->pushHandler(new StreamHandler($this->logFile));

And getting:

[2015-10-21 03:03:39] local.INFO: Test log [] []

Why is [] [] there?

via Chebli Mohamed