minor #979 Improve Tokens::clearEmptyTokens performance (keradus)
minor #979 Improve Tokens::clearEmptyTokens performance (keradus)

This PR was merged into the 2.0-dev branch.

Discussion
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Improve Tokens::clearEmptyTokens performance

Commits
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4d37858 improve Tokens::clearEmptyTokens

keradus/PHP-CS-Fixer,junichi11/PHP-CS-Fixer,keradus/PHP-CS-Fixer,GrahamCampbell/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,gharlan/PHP-CS-Fixer,Soullivaneuh/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,Padam87/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,felixgomez/PHP-CS-Fixer,Soullivaneuh/PHP-CS-Fixer,GrahamCampbell/PHP-CS-Fixer,felixgomez/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,lucasmichot/PHP-CS-Fixer,junichi11/PHP-CS-Fixer,gharlan/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer,lucasmichot/PHP-CS-Fixer,Padam87/PHP-CS-Fixer