Simplify Set::flatMap() Seeds

[Baptouuuu]

Fix #109

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.38%. Comparing base (9bb65c0) to head (eebe4c3).
⚠️ Report is 4 commits behind head on develop.

Additional details and impacted files

@@              Coverage Diff              @@
##             develop     #111      +/-   ##
=============================================
- Coverage      91.44%   91.38%   -0.06%     
+ Complexity      2172     2161      -11     
=============================================
  Files            141      140       -1     
  Lines           9068     9029      -39     
=============================================
- Hits            8292     8251      -41     
- Misses           776      778       +2     

☔ 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.