public function testGenerateRandomBytesCS()
 {
     $sm = new CSecurityManager();
     // any char is allowed so only string length is important
     $mbStrlen = function_exists('mb_strlen');
     for ($i = 1; $i < 255; $i += 1) {
         $ran = $sm->generateRandomBytes($i, true);
         $this->assertInternalType('string', $ran);
         $this->assertEquals($i, $mbStrlen ? mb_strlen($ran, '8bit') : strlen($ran));
     }
 }