code: def get(self, key, default=None):
          
          key = self.make_key(key)
  
          if self.debug:
              return default
  
          try:
              value = self.database[key]
          except KeyError:
              self.metrics['misses'] += 1
              return default
          else:
              self.metrics['hits'] += 1
              return pickle.loads(value)
docs: Retreive a value from the cache. In the event the value
          does not exist, return the ``default``.