code: @Override
      protected void executeImpl(CommandLine cmd) {
          try {
              List<PropertyDefinition> defintions =
                  new PropertyDefinitionListBuilder().addMillDb()
                                                     .addManifestExpirationDate()
                                                     .build();
              PropertyVerifier verifier = new PropertyVerifier(defintions);
              verifier.verify(System.getProperties());
              String time = System.getProperty(ConfigConstants.MANIFEST_EXPIRATION_TIME);
              Date expirationDate;
              expirationDate = parseExpirationDate(time);
  
              ApplicationContext context = new AnnotationConfigApplicationContext("org.duracloud.mill");
              log.info("spring context initialized.");
              ManifestStore store = context.getBean(ManifestStore.class);
              log.info("beginning purge of deleted items");
  
              long deleted = 0l;
              long total = 0l;
              while ((deleted = store.purgeDeletedItemsBefore(expirationDate)) > 0) {
                  total += deleted;
                  log.info("Deleted {} items that were flagged as deleted before {}",
                           deleted,
                           expirationDate);
              }
  
              log.info("Purge completed: Deleted a grand total of {} items that were flagged as deleted before {}",
                       total,
                       expirationDate);
  
          } catch (Exception e) {
              log.error(e.getMessage(), e);
          } finally {
              log.info("exiting...");
          }
      }
docs: /*
  (non-Javadoc)
  
  @see
  org.duracloud.mill.util.DriverSupport#executeImpl(org.apache.commons.
  cli.CommandLine)