/** * @test */ public function it_can_get_and_set_headers() { $message = new Message('test'); $this->assertSame([], $message->getHeaders()); $this->assertFalse($message->getHeader('foo')); $message->setHeader('foo', 'bar'); $this->assertSame(['foo' => 'bar'], $message->getHeaders()); $this->assertSame('bar', $message->getHeader('foo')); }