def __iter__(self):
def _iter_help(tree):<EOL><INDENT>if tree['<STR_LIT>'] is not None:<EOL><INDENT>yield ()<EOL><DEDENT>for st in tree['<STR_LIT>']:<EOL><INDENT>for tail in _iter_help(st[<NUM_LIT:1>]):<EOL><INDENT>yield (st[<NUM_LIT:0>],) + tail<EOL><DEDENT><DEDENT><DEDENT>yield from _iter_help(self.root)<EOL>
Iterate over keys in the tree in "domination order".