To get started, there is an example project named de.hu_berlin.sam.mmunit.example.company available on the update site. After installation, it is available in Eclipse's plugin folder and can be imported as an existing project.
It includes an example metamodel for models that describe company structures (employees, their insurances, and the projects they work on): model/companymm.ecore. It also includes a test specification for this metamodel in model/tests/example_paper.mmunit. You can edit this model by opening the corresponding diagram file model/tests/example_paper.mmunit_diagram. To execute the test specification, there is a test class named ExamplePaperTest that can be executed with JUnit.
Background information can be found in the scientific paper.
If you have any problems, feel free to contact us.