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### Issue Checklist

- [ ] I'm using the latest u3d version
- [ ] I ran `u3d --help`
- [ ] I read the [README](https://github.com/DragonBox/u3d/blob/master/README.md)
- [ ] I made sure that a similar [issue](https://github.com/DragonBox/u3d/issues) doesn't exit

### Issue Description

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[DESCRIBE YOUR ISSUE HERE]