text: from django.core.cache import cache
  
  CACHE_TIMEOUT = 60 * 60 * 1 # one hour
  
  def make_cache_key(visitor_key):
      """ make the cache key for visitor """
      return 'visitor_%s' % (visitor_key)
  
  def check_cache(visitor_key):
      """ check the cache for this visitor """
      cached = cache.get(make_cache_key(visitor_key))
      if cached:
         return cached
         
      return None
  
  def set_cache(visitor):
      """ set the visitor object in the cache """
      if visitor.visitor_key:
          cache_key = make_cache_key(visitor.visitor_key) 
          cache.set(cache_key, visitor, CACHE_TIMEOUT)
  