Fix lazy jfield, add test

[mkitti]

No description provided.

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (master@96353a4). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #164   +/-   ##
=========================================
  Coverage          ?   61.73%           
=========================================
  Files             ?       10           
  Lines             ?      980           
  Branches          ?        0           
=========================================
  Hits              ?      605           
  Misses            ?      375           
  Partials          ?        0           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 96353a4...364c7ce. Read the comment docs.