### Question:
FindChangedTrees extends AbstractGeoGigOp<List<DiffEntry>> { public FindChangedTrees setOldTreeIsh(String oldRefSpec) { this.oldRefSpec = oldRefSpec; return this; }  FindChangedTrees setPathFilter(@Nullable List<String> pathFitlers); FindChangedTrees setLeftSource(ObjectStore leftSource); FindChangedTrees setRightSource(ObjectStore rightSource); FindChangedTrees setOldTreeIsh(String oldRefSpec); FindChangedTrees setNewTreeIsh(String newRefSpec); FindChangedTrees setOldTreeIsh(ObjectId oldTreeId); FindChangedTrees setNewTreeIsh(ObjectId newTreeId); FindChangedTrees setOldTreeIsh(RevTree oldTree); FindChangedTrees setNewTreeIsh(RevTree newTree);  }### Answer:
public @Test void testNoNewVersionSet() { command.setOldTreeIsh(Ref.HEAD); Exception e = assertThrows(IllegalArgumentException.class, command::call); assertThat(e.getMessage(), containsString("new version")); }