public function testVisibilityPrivate()
 {
     if (IS_WINDOWS) {
         $this->markTestSkipped("Visibility not supported on Windows.");
     }
     $this->adapter->write('path.txt', 'contents', new Config());
     $this->adapter->setVisibility('path.txt', 'private');
     $output = $this->adapter->getVisibility('path.txt');
     $this->assertInternalType('array', $output);
     $this->assertArrayHasKey('visibility', $output);
     $this->assertEquals('private', $output['visibility']);
 }