code: private boolean hasContentInVfsOrImport(CmsResource resource) {
  
          if (m_contentFiles.contains(resource.getResourceId())) {
              return true;
          }
          try {
              List<CmsResource> resources = getCms().readSiblings(resource, CmsResourceFilter.ALL);
              if (!resources.isEmpty()) {
                  return true;
              }
          } catch (CmsException e) {
              LOG.warn(e.getLocalizedMessage(), e);
          }
          return false;
  
      }
docs: Checks whether the content for the resource being imported exists either in the VFS or in the import file.<p>
  
  @param resource the resource which should be checked
  
  @return true if the content exists in the VFS or import file