Added testing to test_maps.py

[ghost]

[x] Wrote test for feature
[ ] Added changes to CHANGELOG.md

Changes proposed:
Added additional tests to tests_maps.py to increase testing as stated on #476.

[adnanhemani]

As shown by the CI/CD results, I don't think this code was properly tested locally prior to being raised as a PR here. Please ensure that any code you push here (for the sake of being a reasonable use of maintainers' efforts) does the following: 1) passes all unit testing and 2) increases the test coverage of the repository. This is not explicitly mentioned anywhere in this repo as it is Open Source standard - and general, good practice.

I will keep this PR open for a week to allow you to make any further changes for a chance to revise this code.