This patch refactors the tests suite to use a base class to declare test cases
just using a class declaration, the existing test class was modified to use it
and new tests are using it as well.
These tests verify the XML generated when the 'node' option is set and
when it's absent.
Change-Id: Iddcdd63e0ab7c459f6513b1d1ebf19e19a362c1d