Fix signatures

[meggart]

This fixes a few corner cases when the name of an array to be added to a group is not a plain String

[coveralls]

Pull Request Test Coverage Report for Build 2269794006

• 3 of 3 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 85.584%

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Totals
Change from base Build 1991633816:	0.2%
Covered Lines:	659
Relevant Lines:	770

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 2269794006

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 3 of 3 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 85.584%

---

Totals
Change from base Build 1991633816:	0.2%
Covered Lines:	659
Relevant Lines:	770

---

💛 - Coveralls