public function testValidateContent()
 {
     $textFile = vfsStream::newFile('foo.txt');
     $textFile->setContent('foo');
     $this->dir->addChild($textFile);
     $this->assertFalse($this->provider->validateContent(NULL));
     $this->assertFalse($this->provider->validateContent(1234));
     $this->assertFalse($this->provider->validateContent(vfsStream::url('root/foo.txt')));
     $imagePath = vfsStream::url('root/sample.jpg');
     $this->assertTrue($this->provider->validateContent($imagePath));
     $this->assertTrue($this->provider->validateContent(new \SplFileInfo($imagePath)));
 }