### Question:
WorkObject extends ContentContainerObject { public void clearPrimaryObject() { repoObjFactory.deleteProperty(this, Cdr.primaryObject); } protected  WorkObject(PID pid, RepositoryObjectDriver driver, RepositoryObjectFactory repoObjFactory); @Override WorkObject validateType(); void clearPrimaryObject(); void setPrimaryObject(PID primaryPid); FileObject getPrimaryObject(); @Override ContentContainerObject addMember(ContentObject member); FileObject addDataFile(URI storageUri, String filename, String mimetype,
            String sha1Checksum, String md5Checksum); FileObject addDataFile(URI storageUri, String filename,
            String mimetype, String sha1Checksum, String md5Checksum, Model model); FileObject addDataFile(PID filePid, URI storageUri, String filename,
            String mimetype, String sha1Checksum, String md5Checksum, Model model);  }### Answer:
@Test public void clearPrimaryObjectTest() { work.clearPrimaryObject(); verify(repoObjFactory).deleteProperty(eq(work), eq(Cdr.primaryObject)); }