@abc.abstractmethod<EOL><INDENT>def get_values(self):<DEDENT>
return<EOL>
Gets all the values in this configuration.

        In plenary mode, all values are returned or an error results. In
        comparative mode, inaccessible values may be omitted.

        In plenary mode, the returned list contains all known values or
        an error results. Otherwise, the returned list may contain only
        those values that are accessible through this session.

        In active mode, values are returned that are currently active.
        In any status mode, active and inactive values are returned.

        :return: the value list
        :rtype: ``osid.configuration.ValueList``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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