docs: def load_mo(self, state, page_idx):
          """
          Loads a memory object from memory.
  
          :param page_idx: the index into the page
          :returns: a tuple of the object
          """
  
          try:
              key = next(self._storage.irange(maximum=page_idx, reverse=True))
          except StopIteration:
              return None
          else:
              return self._storage[key]