### Question:
MetadataService extends AbstractService { @SuppressWarnings("unchecked") public Collection<Entry> usedBy(Project project, Obj obj, boolean nearest, Class<? extends Obj>... types) { notNull(obj, "obj"); return usedBy(project, obj.getUri(), nearest, types); } MetadataService(final RestTemplate restTemplate, final GoodDataSettings settings); @SuppressWarnings("unchecked") T createObj(Project project, T obj); T getObjByUri(String uri, Class<T> cls); Collection<Obj> getObjsByUris(Project project, Collection<String> uris); @SuppressWarnings("unchecked") T updateObj(T obj); void removeObj(Obj obj); void removeObjByUri(String uri); T getObjById(Project project, String id, Class<T> cls); String getObjUri(Project project, Class<T> cls, Restriction... restrictions); T getObj(Project project, Class<T> cls, Restriction... restrictions); Collection<Entry> find(Project project, Class<T> cls, Restriction... restrictions); Collection<String> findUris(Project project,
                                                             Class<T> cls,
                                                             Restriction... restrictions); @SuppressWarnings("unchecked") Collection<Entry> usedBy(Project project, Obj obj, boolean nearest, Class<? extends Obj>... types); @SuppressWarnings("unchecked") Collection<Entry> usedBy(Project project, String uri, boolean nearest, Class<? extends Obj>... types); @SuppressWarnings("unchecked") Collection<Usage> usedBy(Project project, Collection<String> uris, boolean nearest, Class<? extends Obj>... types); Collection<String> findUris(Project project, Restriction... restrictions); Map<String, String> identifiersToUris(Project project, Collection<String> identifiers); List<AttributeElement> getAttributeElements(Attribute attribute); List<AttributeElement> getAttributeElements(DisplayForm displayForm); static final UriTemplate OBJ_TEMPLATE; }### Answer:
@Test(expectedExceptions = IllegalArgumentException.class) public void testUsedByNullProject() { service.usedBy(null, URI, false, ReportDefinition.class); }