FileLogger::error PHP 메소드

    public function error($message)
    {
        return $this->write($message, 'error');
    }

 function testFileLoggerErrorLevel()
 {
     $buffer = fopen('php://memory', 'rw');
     $logger = new FileLogger($buffer, ILogger::ERROR);
     $logger->debug('debug message');
     $logger->info('info message');
     $logger->error('error message');
     $this->assertTrue(rewind($buffer));
     $out = fread($buffer, 5000);
     $this->assertEqual($out, "error message\n");
 }