fixed bug in generate_data and adapted tests #72

All 13 tests pass in 1s

1 files ±0 7 suites ±0 1s ⏱️ ±0s
13 tests ±0 13 ✅ ±0 0 💤 ±0 0 ❌ ±0
20 runs ±0 20 ✅ ±0 0 💤 ±0 0 ❌ ±0

Results for commit 02baafa. ± Comparison against earlier commit a12a939.