Increase test coverage

[pluma]

[thomasmodeneis]

Where test coverage increase is needed ?
Could you please elaborate this ?

[pluma]

Just run the tests and look for "is missing tests". There are a number of methods that don't currently have any test coverage, so adding tests for these would be a priority. These are currently stubbed out in the test directory to make it obvious which methods are known not to have tests yet.

[pluma]

Fixed via #519.