code: def __build_directory_levels(self):
          
  
          previous_level_blocks = [ self.__root ]
  
          for level in range(1, self.__levels):
              previous_level_blocks = self.__build_level(previous_level_blocks, level)
              self.__store_level_blocks(previous_level_blocks)
  
          self.__leafs = sorted(self.__leafs, key=lambda block: block.get_density())
docs: !
          @brief Build levels of direction if amount of level is greater than one.