Warn the user when output cells get omitted

[akarve]

No description provided.

[codecov-commenter]

Codecov Report

Merging #1823 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1823   +/-   ##
=======================================
  Coverage   89.49%   89.49%           
=======================================
  Files          62       62           
  Lines        7233     7236    +3     
=======================================
+ Hits         6473     6476    +3     
  Misses        760      760           

Flag	Coverage Δ
#api-python	87.87% <ø> (ø)
#lambda	92.33% <100.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
lambdas/preview/index.py	98.30% <100.00%> (+0.04%)	⬆️

---

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 a5945a1...0a814b8. Read the comment docs.