add `check_ard_structure()` unit tests #305

All 105 tests pass, 32 skipped in 1m 4s

1 files ± 0 138 suites +4 1m 4s ⏱️ ±0s
137 tests + 4 105 ✅ - 28 32 💤 +32 0 ❌ ±0
532 runs - 78 488 ✅ - 122 44 💤 +44 0 ❌ ±0

Results for commit 670dc6d. ± Comparison against earlier commit 163a394.