code: public SwiftCachedObject get(final String objName) throws IOException {
      LOG.trace("Get from cache: {}", objName);
      SwiftCachedObject res = cache.get(objName);
      if (res == null) {
        LOG.trace("Cache get: {} is not in the cache. Access Swift to get content length", objName);
        StoredObject rawObj = container.getObject(removeTrailingSlash(objName));
        if (rawObj != null && rawObj.exists()) {
          res = new SwiftCachedObject(rawObj.getContentLength(),
            Utils.lastModifiedAsLong(rawObj.getLastModified()));
          put(objName, res);
        } else {
          return null;
        }
      }
      return res;
    }
docs: The get function will first search for the object in the cache.
  If not found will issue a HEAD request for the object metadata
  and add the object to the cache.
  
  @param objName object name
  @return cached entry of the object
  @throws IOException if failed to parse time stamp