def binary_tree_mirror(binary_tree: dict, root: int = 1) -> dict:
    if not binary_tree:
        raise ValueError("binary tree cannot be empty")
    if root not in binary_tree:
        raise ValueError(f"root {root} is not present in the binary_tree")
    binary_tree_mirror_dictionary = dict(binary_tree)
    binary_tree_mirror_dict(binary_tree_mirror_dictionary, root)
    return binary_tree_mirror_dictionary