def apply_mixin(dct, key, func, *args, **kwargs):
    """Apply in-place data mutation to a dictionary.

    :param dict dct:
        Dictionary to apply mixin function to.
    :param str key:
        Key within dictionary to apply mixin function to.
    :param callable func:
        Transform function to apply to ``dct[key]``.
    :param \\*args:
        (optional) positional arguments that ``func`` takes.
    :param \\*\\*kwargs:
        (optional) keyword arguments that ``func`` takes.
    :rtype:
        None
    """
    dct[key] = func(dct[key], *args, **kwargs)
