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