Fixes #868: Fix removing items from list, which is being iterated

[dolamroth]

Fixes #868

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.27%. Comparing base (05e7ffa) to head (06de2f3).
⚠️ Report is 6 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #869   +/-   ##
=======================================
  Coverage   82.27%   82.27%           
=======================================
  Files          80       80           
  Lines        6844     6844           
=======================================
  Hits         5631     5631           
  Misses       1213     1213           

Flag	Coverage Δ
unittests	82.27% <100.00%> (ø)

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

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[haeter525]

Thank you @dolamroth for helping resolving the potential skipped-element issue!