know that that it is application specific, it's not part of the specification.
    """

    def __init__(
        self,
        *,
        grant_type: Annotated[
            Union[str, None],
            Form(pattern="password"),
            Doc(
                """
                The OAuth2 spec says it is required and MUST be the fixed string
                "password". Nevertheless, this dependency class is permissive and