Online PHP editor | refs for upa2A

<?php function isCorrect() { return true; } assert(isCorrect('') === true); assert(isCorrect('()') === true); assert(isCorrect('{()}') === true); assert(isCorrect('{()}{}') === true); assert(isCorrect('(())') === true); assert(isCorrect('{({({({()})})})}') === true); assert(isCorrect('{(})') === false);