code: def generator(self, size=1000, tree_depth=1):
          
          if not tree_depth:
              return self._map_type()
          return (self.generator(size, tree_depth-1) for x in range(size))
docs: Creates a random #generator
  
              @size: #int number of random values to include in each @tree_depth
              @tree_depth: #int dict tree dimensions size, i.e.
                  1=|(value1, value2)|
                  2=|((value1, value2), (value1, value2))|
  
              -> random :class:collections.deque