public function testRead()
 {
     $mock = $this->getS3Client();
     $mock->shouldReceive('getObject')->once()->andReturn(Mockery::self());
     $mock->shouldReceive('getAll')->once()->andReturn(['ContentLength' => 10, 'ContentType' => 'text/plain', 'Body' => '1234567890', 'Key' => 'file.ext']);
     $adapter = new Adapter($mock, 'bucketname');
     $result = $adapter->read('file.ext');
     $this->assertEquals('1234567890', $result['contents']);
 }