make update() work even if there are many duplicate indices

[ilia-kats]

closes #107

[codecov]

Codecov Report

❌ Patch coverage is 93.33333% with 1 line in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (main@ddbcfa4). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
tests/test_update.py	93.33%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #108   +/-   ##
=======================================
  Coverage        ?   96.81%           
=======================================
  Files           ?       13           
  Lines           ?      880           
  Branches        ?        0           
=======================================
  Hits            ?      852           
  Misses          ?       28           
  Partials        ?        0           

Files with missing lines	Coverage Δ
tests/test_update.py	91.66% <93.33%> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[ilan-gold]

Could you add a test for this?

[ilia-kats]

done