code: def has_storage(self, address):
          
          storage = self._world_state[address]['storage']
          array = storage.array
          while not isinstance(array, ArrayVariable):
              if isinstance(array, ArrayStore):
                  return True
              array = array.array
          return False
docs: True if something has been written to the storage.
          Note that if a slot has been erased from the storage this function may
          lose any meaning.