public function testWithHeader()
 {
     // ARRANGE
     $request = new Request(new SymfonyRequest());
     // ACT
     $result = $request->withHeader('User-Agent', 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:38.0) Gecko/20100101 Firefox/38.0');
     // ASSERT
     $this->assertInstanceOf('\\SamBurns\\Psr7Symfony\\Request', $result);
     $this->assertEquals('Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:38.0) Gecko/20100101 Firefox/38.0', $result->getHeader('User-Agent'));
     $result = $request->withProtocolVersion('1.1');
     $this->assertEquals('1.1', $result->getProtocolVersion());
 }