def square_brackets(s):
    """
    Surrounds the string with ⟦ ⟧ characters.  Useful when verifying string
    truncation i.e. when checking the UI these characters should be visible.

    :param s: String to surround
    :returns: String surrounded with ⟦ ⟧
    """
    return u'⟦{0}⟧'.format(s)
