from typing import Dict
from typing import Any


def dict_to_indented_tree(d: Dict[str, Any]) -> str:
    """ Convert a dict-formatted tree into a single string, in indented tree format """

    def append_children(d, indent_lvl):
        subtree = ''
        for k, v in d.items():
            subtree += ' ' * indent_lvl + k + '\n'
            subtree += append_children(v, indent_lvl + 1)
        return subtree

    return append_children(d, 0)