code: public boolean isRevisitNotModified() {
  		Map<String, Object> warcHeaders = getWarcHeaders().getHeaderFields();
  		String warcProfile = (String)warcHeaders.get("WARC-Profile");
  		return PROFILE_REVISIT_SERVER_NOT_MODIFIED.equals(warcProfile);
  	}
docs: whether this Resource is {@code server-not-modified} revisit.
  (this method used to be {@code AccessPoint#isWarcRevisitNotModified(Resource)}.
  Not made a part of {@code Resource} interface because it was unused.)
  @return {@code true} if it is