code: @SuppressWarnings("null")
    public static @Nullable Date get(@Nullable Resource resource) {
      if (resource == null) {
        return null;
      }
      ValueMap resourceProperties = resource.getValueMap();
  
      // get the cq:lastModified property from the resource (used in jcr:content nodes of cq pages)
      Date cqModified = resourceProperties != null ? resourceProperties.get(NameConstants.PN_PAGE_LAST_MOD, Date.class) : null;
  
      // try to find a jcr:lastModified property that is used for binary uploads or cq paragraphs
      Date resourceModified = getResourceMetadataModificationTime(resource);
  
      // get the most recent date of both
      return mostRecent(cqModified, resourceModified);
    }
docs: Looks for either jcr:lastModified or cq:lastModified property in the given resource, which can be either the jcr:content-ode of a cq-page, or a rendition
  node
  @param resource a resource with a cq:lastModified property *and/or* a file/jcr:content subnode with a jcr:lastModified property
  @return the date or null if last modified property could not be found