getExpectedAsString example

// make 'foo' directory non-readable         $testDir = self::$tmpDir.\DIRECTORY_SEPARATOR.'foo';
        chmod($testDir, 0333);

        if (false === $couldRead = is_readable($testDir)) {
            try {
                $this->assertIterator($this->toAbsolute(['foo bar', 'test.php', 'test.py']), $finder->getIterator());
                $this->fail('Finder should throw an exception when opening a non-readable directory.');
            } catch (\Exception $e) {
                $expectedExceptionClass = 'Symfony\\Component\\Finder\\Exception\\AccessDeniedException';
                if ($e instanceof \PHPUnit\Framework\ExpectationFailedException) {
                    $this->fail(sprintf("Expected exception:\n%s\nGot:\n%s\nWith comparison failure:\n%s", $expectedExceptionClass, 'PHPUnit\Framework\ExpectationFailedException', $e->getComparisonFailure()->getExpectedAsString()));
                }

                $this->assertInstanceOf($expectedExceptionClass, $e);
            }
        }

        // restore original permissions         chmod($testDir, 0777);
        clearstatcache(true, $testDir);

        if ($couldRead) {