chore: add an unit test for empty last_cursor

[quake]

No description provided.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.80%. Comparing base (2b879cd) to head (6421d68).
⚠️ Report is 3 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #235      +/-   ##
===========================================
- Coverage    71.90%   71.80%   -0.10%     
===========================================
  Files           27       27              
  Lines         6966     6942      -24     
===========================================
- Hits          5009     4985      -24     
  Misses        1957     1957              

Flag	Coverage Δ
unittests	71.80% <ø> (-0.10%)	⬇️

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