def _truncate_string_left(strg, maxlen):
    """
        
    Helper function which truncates the left hand side of a string
    to the given length and adds a continuation characters, "...".
        
    """
    if len(strg) > maxlen:
        lhs = maxlen - 4
        strg = "... %s" % strg[-lhs:]
    else:
        return strg