def METHOD_NAME(self, function: t.Callable[[T], To]) -> Params[To]:
    """
    Apply a function to all the values in the Params and return a Params of the
    return values.
    """
    args = tuple(function(a) for a in self.args)
    kwargs = {k: function(v) for k, v in self.kwargs.items()}
    return Params[To](*args, **kwargs)