@group_id.setter<EOL><INDENT>def group_id(self, value):<DEDENT>
if isinstance(value, GroupId):<EOL><INDENT>self._group_id = value<EOL><DEDENT>else:<EOL><INDENT>self._group_id = GroupId(value)<EOL><DEDENT>
The unsubscribe group to associate with this email.

        :param value: ID of an unsubscribe group
        :type value: GroupId, int, required