from typing import Dict


def dict_delete_none_fields(d: Dict):
    """Remove all keys that have "None" values in a dict.

    :param d: The dictionary to sanitize
    :return: The dict instance with all "None keys" removed
    """
    for k, v in list(d.items()):
        if v is None:
            del d[k]
        elif isinstance(v, dict):
            dict_delete_none_fields(v)
    return d