SparkPost\Test\SparkPostTest::testPromise PHP Method

    public function testPromise()
    {
        $promiseMock = Mockery::mock('Http\\Promise\\Promise');
        $this->clientMock->shouldReceive('sendAsyncRequest')->once()->with(Mockery::type('GuzzleHttp\\Psr7\\Request'))->andReturn($promiseMock);
        $promise = $this->resource->asyncRequest('POST', 'transmissions', $this->postTransmissionPayload);
        $promiseMock->shouldReceive('getState')->twice()->andReturn('pending');
        $this->assertEquals($promiseMock->getState(), $promise->getState());
        $promiseMock->shouldReceive('getState')->once()->andReturn('rejected');
        $this->assertEquals('rejected', $promise->getState());
    }