code: private Link verify(Link link) {
  
  		Assert.notNull(link, "Link must not be null!");
  
  		try {
  
  			String uri = link.expand().getHref();
  
  			this.log.debug("Verifying link pointing to {}…", uri);
  			this.restOperations.headForHeaders(uri);
  			this.log.debug("Successfully verified link!");
  
  			return link;
  
  		}
  		catch (RestClientException o_O) {
  
  			this.log.debug("Verification failed, marking as outdated!");
  			return null;
  		}
  	}
docs: Verifies the given {@link Link} by issuing an HTTP HEAD request to the resource.
  @param link Must not be {@literal null}.
  @return - link to the resource