Description
   Use this to save a resource after retrieving.  Since the cache_ttl
   configuration variable is used in determining when to check the remote server, and
   HTTP caching is used as well, it is possible for this scenario to arise:
  
   
      retrieve REST resource
     
      cache the resource
     
      a few days later, retrieve the REST resource again
     
      HTTP caching returns 304 not modified
     
  
   In this situation, it doesn't make much sense to save the resource contents
   redundantly.  Instead, the last access time can be saved in the cache id by passing
   true into the last parameter.