### Question:
MavenModelMerger extends ModelMerger { @Override protected void mergeModel_ArtifactId( Model target, Model source, boolean sourceDominant, Map<Object, Object> context ) { }   static final String CHILD_PATH_ADJUSTMENT; static final String ARTIFACT_ID; }### Answer:
@Test public void testMergeModel_ArtifactId() { Model parent = new Model(); parent.setArtifactId( "PARENT" ); Model model = new Model(); modelMerger.mergeModel_ArtifactId( model, parent, false, null ); assertNull( model.getArtifactId() ); model.setArtifactId( "MODEL" ); modelMerger.mergeModel_ArtifactId( model, parent, false, null ); assertEquals( "MODEL", model.getArtifactId() ); }