This property returns the commit message's body, which is the part after

the summary, if it's available. It will be used as part of a fix for the

diff commit list.
Unit tests are added. The old test suite had setup code that was very

specific to the tests that were initially written, so some cleanup was

done to move that setup code into a dedicated, optional function.

Unit tests pass.
Made use of this function in some upcoming code.