@abc.abstractmethod<EOL><INDENT>def remove_root_objective_bank(self, objective_bank_id):<DEDENT>
pass<EOL>
Removes a root objective bank.

        :param objective_bank_id: the ``Id`` of an objective bank
        :type objective_bank_id: ``osid.id.Id``
        :raise: ``NotFound`` -- ``objective_bank_id`` is not a root
        :raise: ``NullArgument`` -- ``objective_bank_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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