## Before you submit
Make sure your issue is not already in the [htsjdk issue tracker](https://github.com/samtools/htsjdk/issues?q=)

### Description of the issue:
Describe your issue here.
Provide **screenshots** , **stacktraces** , or **logs** where appropriate.

### Your environment:
* version of htsjdk
* version of java
* which OS

### Steps to reproduce
If you're reporting a bug, tell us how to reproduce this issue. If possible, include a short **code snippet** or attach **test data** to demonstrate the problem.

### Expected behaviour
Tell us what should happen.

### Actual behaviour
Tell us what happens instead.
