public function itShouldFail($success)
    {
        if ('fail' === $success) {
            if (0 === $this->getExitCode()) {
                echo 'Actual output:'.PHP_EOL.PHP_EOL.$this->getOutput();
            }

            \PHPUnit_Framework_Assert::assertNotEquals(0, $this->getExitCode());
        } else {
            if (0 !== $this->getExitCode()) {
                echo 'Actual output:'.PHP_EOL.PHP_EOL.$this->getOutput();
            }

            \PHPUnit_Framework_Assert::assertEquals(0, $this->getExitCode());
        }
    }