TYP: hashing
- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [ ] whatsnew entry

lgtm. @simonjayhawkins if you have a chance. if theres no interest here we can close it to clear the queue > if theres no interest here we can close it to clear the queue

its fine, this is worth merging.