Type preservation

[znicholls]

Closes #163

[trexfeathers]

Thanks so much for your contribution @znicholls! And sorry for letting this go stale.

Please could you rebase, and service my suggestion for making the code more generic?

[codecov]

Codecov Report

Merging #164 (4edec8a) into master (02ae952) will increase coverage by 0.13%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #164      +/-   ##
==========================================
+ Coverage   90.48%   90.61%   +0.13%     
==========================================
  Files           7        7              
  Lines         830      831       +1     
  Branches      105      105              
==========================================
+ Hits          751      753       +2     
  Misses         64       64              
+ Partials       15       14       -1     

Impacted Files	Coverage Δ
cf_units/__init__.py	89.53% <100.00%> (+0.23%)	⬆️

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[znicholls]

sorry for letting this go stale

No worries, lots happening

Please could you rebase, and service my suggestion for making the code more generic?

Done