We use the issue tracker to track bugs with mgo - if you have a usage question,
it's best to try Stack Overflow :)

Replace this text with your description, and please answer the questions below
before submitting your issue to help us out. Thanks!

-------------------------------------------------------------------------------

### What version of MongoDB are you using (`mongod --version`)?
```
<mongodb version here>
```

### What version of Go are you using (`go version`)?
```
<go version here>
```

### What operating system and processor architecture are you using (`go env`)?
```
<go env here>
```

### What did you do?

If possible, provide a recipe for reproducing the error.
A runnable program is great and really helps!

### Can you reproduce the issue on the latest `development` branch?