@abc.abstractmethod<EOL><INDENT>def get_time_set(self):<DEDENT>
return<EOL>
Gets the set of acceptable time values.

        :return: a set of times or an empty array if not restricted
        :rtype: ``osid.calendaring.Time``
        :raise: ``IllegalState`` -- syntax is not a ``TIME``

        *compliance: mandatory -- This method must be implemented.*