code: protected List<CmsUUID> undelete() throws CmsException {
  
          List<CmsUUID> modifiedResources = new ArrayList<CmsUUID>();
          CmsObject cms = m_context.getCms();
          for (CmsResource resource : m_context.getResources()) {
              CmsLockActionRecord actionRecord = null;
              try {
                  actionRecord = CmsLockUtil.ensureLock(m_context.getCms(), resource);
                  cms.undeleteResource(cms.getSitePath(resource), true);
                  modifiedResources.add(resource.getStructureId());
              } finally {
                  if ((actionRecord != null) && (actionRecord.getChange() == LockChange.locked)) {
  
                      try {
                          cms.unlockResource(resource);
                      } catch (CmsLockException e) {
                          LOG.warn(e.getLocalizedMessage(), e);
                      }
                  }
              }
          }
          return modifiedResources;
      }
docs: Undeletes the selected files
  
  @return the ids of the modified resources
  
  @throws CmsException if something goes wrong