@abc.abstractmethod<EOL><INDENT>def set_start_time(self, start):<DEDENT>
pass<EOL>
Sets the assessment start time.

        :param start: assessment start time
        :type start: ``osid.calendaring.DateTime``
        :raise: ``InvalidArgument`` -- ``start`` is invalid
        :raise: ``NoAccess`` -- ``Metadata.isReadOnly()`` is ``true``

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