public function testGetErrorOutput() {
$p = new Process(sprintf('php -r %s', escapeshellarg('$n = 0; while ($n < 3) { file_put_contents(\'php://stderr\', \'ERROR\'); $n++; }')));
$p
->run();
$this
->assertEquals(3, preg_match_all('/ERROR/', $p
->getErrorOutput(), $matches));
}