:param dimensions:
            A tuple of (width, height, force_size).
            'force_size' can be left off and will default to False.

def _get_resize_options(self, dimensions):
        """
        :param dimensions:
            A tuple of (width, height, force_size).
            'force_size' can be left off and will default to False.
        """
        if dimensions and isinstance(dimensions, (tuple, list)):
            if len(dimensions) < 3:
                dimensions = tuple(dimensions) + (False, )
            return dimensions