import typing


def translate_null_strings_to_blanks(d: typing.Dict) -> typing.Dict:
    """Map over a dict and translate any null string values into ' '.
    Leave everything else as is. This is needed because you cannot add TableCell
    objects with only a null string or the client crashes.

    :param Dict d: dict of item values.
    :rtype Dict:
    """

    # Beware: locally defined function.
    def translate_nulls(s):
        if s == "":
            return " "
        return s

    new_d = {k: translate_nulls(v) for k, v in d.items()}
    return new_d