def METHOD_NAME(text):
    '''Return tuple of 'line.col' indexes from selection or insert mark.
    '''
    try:
        first = text.index("sel.first")
        last = text.index("sel.last")
    except TclError:
        first = last = None
    if not first:
        first = text.index("insert")
    if not last:
        last = first
    return first, last