def is_position_aes(vars_):
    """
    Figure out if an aesthetic is a position aesthetic or not
    """
    try:
        return all([aes_to_scale(v) in {'x', 'y'} for v in vars_])
    except TypeError:
        return aes_to_scale(vars_) in {'x', 'y'}
Figure out if an aesthetic is a position aesthetic or not