GuzzleHttp\Test\Handler\StreamHandlerTest::testDoesNotAddContentTypeByDefault PHP Method

    public function testDoesNotAddContentTypeByDefault()
    {
        $this->queueRes();
        $handler = new StreamHandler();
        $request = new Request('PUT', Server::$url, ['Content-Length' => 3], 'foo');
        $handler($request, []);
        $req = Server::received()[0];
        $this->assertEquals('', $req->getHeaderLine('Content-Type'));
        $this->assertEquals(3, $req->getHeaderLine('Content-Length'));
    }