Doctrine\MongoDB\Connection::setMongo PHP Method

    public function setMongo($mongoClient)
    {
        if (!($mongoClient instanceof \MongoClient || $mongoClient instanceof \Mongo)) {
            throw new \InvalidArgumentException('MongoClient or Mongo instance required');
        }
        $this->mongoClient = $mongoClient;
    }

 /**
  * @expectedException InvalidArgumentException
  */
 public function testSetMongoShouldThrowExceptionForInvalidArgument()
 {
     $mongoDB = $this->getMockBuilder('MongoDB')->disableOriginalConstructor()->getMock();
     $conn = new Connection();
     $conn->setMongo($mongoDB);
 }