Core: Error handler (FE): PHP Warning: Declaration of x should be compatible with y

[bihor]

I get this warning in the "Protokoll" with the branch for TYPO3 7:

Core: Error handler (FE): PHP Warning: Declaration of Tollwerk\TwAntibot\ViewHelpers\AccessViewHelper::_validate($argument) should be compatible with Tollwerk\TwAntibot\ViewHelpers\AbstractAntibotViewHelper::_validate($argument = NULL) in /html/typo3/typo3conf/ext/tw_antibot/Classes/ViewHelpers/AccessViewHelper.php line 35

Simple solution: make it compatible. Add "= null" at the _validate method in AccessViewHelper.php:
protected function _validate($argument = null)