If the received token is one of the keys of $aFilterTokenFunctions a function with the same name of the value of that key is called. If the method doesn't exists, __call() is called, and return PHP_Beautifier_Filter::BYPASS. PHP_Beautifier, now, call the next Filter is its list. If the method exists, it can return true or PHP_Beautifier_Filter::BYPASS.
Return: true if the token is processed, false bypass to the next Filter