def dot_to_dict(values: Dict[str, Any]) -> Dict[str, dict]:
    """Convert dot notation to a dict. For example: {"token.pos": True,
    "token._.xyz": True} becomes {"token": {"pos": True, "_": {"xyz": True }}}.

    values (Dict[str, Any]): The key/value pairs to convert.
    RETURNS (Dict[str, dict]): The converted values.
    """
    result: Dict[str, dict] = {}
    for key, value in values.items():
        path = result
        parts = key.lower().split(".")
        for i, item in enumerate(parts):
            is_last = i == len(parts) - 1
            path = path.setdefault(item, value if is_last else {})
    return result
Convert dot notation to a dict. For example: {"token.pos": True,
    "token._.xyz": True} becomes {"token": {"pos": True, "_": {"xyz": True }}}.

    values (Dict[str, Any]): The key/value pairs to convert.
    RETURNS (Dict[str, dict]): The converted values.
    
spacy/util.py