code: public static boolean handleIfModifiedSince(final String modifiedSince, final Date lastModified) {
          if (lastModified == null) {
              return true;
          }
          if (modifiedSince == null) {
              return true;
          }
          Date modDate = parseDate(modifiedSince);
          if (modDate == null) {
              return true;
          }
          return lastModified.getTime() > (modDate.getTime() + 999); //UNDERTOW-341 +999 as there is no millisecond part in the if-modified-since
      }
docs: Handles the if-modified-since header. returns true if the request should proceed, false otherwise
  
  @param modifiedSince the modified since date
  @param lastModified  The last modified date
  @return