```py
    >>> from datasets import Features, ClassLabel
    >>> features = Features({'label': ClassLabel(num_classes=3, names=['bad', 'ok', 'good'])})
    >>> features
    {'label': ClassLabel(names=['bad', 'ok', 'good'], id=None)}
    ```
    """

    num_classes: InitVar[Optional[int]] = None  # Pseudo-field: ignored by asdict/fields when converting to/from dict
    names: List[str] = None
    names_file: InitVar[Optional[str]] = None  # Pseudo-field: ignored by asdict/fields when converting to/from dict
    id: Optional[str] = None
    # Automatically constructed
    dtype: ClassVar[str] = "int64"
    pa_type: ClassVar[Any] = pa.int64()
    _str2int: ClassVar[Dict[str, int]] = None
    _int2str: ClassVar[Dict[int, int]] = None
    _type: str = field(default="ClassLabel", init=False, repr=False)