Fix 'Split' interfaces classes, update library version to v0.0.12

[AlexTxen]

Fixed 'Split' interface classes. Updated library version to 0.0.12 Closes #83

[Erik0x42]

Strictly speaking we are lacking some PR policies with regard to - among other things - mandatory issue association and merge philosophy (eg, restricting to squash merge, which would be more forgiving with regard to constituent commits' message wording?). But I guess we can agree to apply these two policy items manually on this PR, and then take a concerted action through #82

• [ ] There should be an issue created and linked to this PR.

If we could agree to use squash merge for this PR - so that the PR title becomes the commit message on main, then I would suggest to

• [ ] change the PR title to: "Fix Split interfaces classes, bump to v0.0.12", and
• [ ] update PR description to match, and
• [ ] update the changelog entry to match