code: def delete(self, key, cache=None):
          
          if cache is None:
              cache = self.name
          if cache is None:
              raise ValueError("Cache name must be set")
          cache = quote_plus(cache)
          key = quote_plus(key)
  
          self.client.delete("caches/%s/items/%s" % (cache, key))
  
          return True
docs: Query the server to delete the key specified from the cache
          specified.
  
          Keyword arguments:
          key -- the key the item is stored under. Required.
          cache -- the cache to delete the item from. Defaults to None, which
                   uses self.name. If no name is set, raises a ValueError.