public function setUp()
{
$this->msg = ['data' => 'hello world', 'messageId' => '1234', 'publishTime' => (new \DateTime())->format('c'), 'attributes' => ['browser-name' => 'Google Chrome']];
$subscription = $this->prophesize(Subscription::class);
$subscription->name()->willReturn(self::SUBSCRIPTION);
$this->metadata = ['ackId' => '4321', 'subscription' => $subscription->reveal()];
$this->message = new Message($this->msg, $this->metadata);
}