Online PHP editor | output for LkDjR

<?php class PHPApprentice { private static $velocity = ''; private static $initialized = false; public static function initialize () { if ( self::initialized ) return; self::$initialized = true; self::$velocity = 'fast!'; } public static function getVelocity () { self::initialize(); return self::$velocity; } public static function setVelocity ( $value ) { self::$velocity = $value; self::initialized = true; } } PHPApprentice::setVelocity ( 'Ludicrous Speed!!' ); echo PHPApprentice::getVelocity();