def extract_selector_info(sel):
    """Return selector special pseudo class info (steps and other)."""
    #  walk the parsed_tree, looking for pseudoClass selectors, check names
    # add in steps and/or deferred extras
    steps, extras = _extract_sel_info(sel.parsed_tree)
    steps = sorted(set(steps))
    extras = sorted(set(extras))
    if len(steps) == 0:
        steps = ['default']
    return (steps, extras)