def get_repository(self, repository_id=None):
        """Gets the ``Repository`` specified by its ``Id``.

        In plenary mode, the exact ``Id`` is found or a ``NotFound``
        results. Otherwise, the returned ``Repository`` may have a
        different ``Id`` than requested, such as the case where a
        duplicate ``Id`` was assigned to a ``Repository`` and retained
        for compatibility.

        arg:    repository_id (osid.id.Id): ``Id`` of the ``Repository``
        return: (osid.repository.Repository) - the repository
        raise:  NotFound - ``repository_id`` not found
        raise:  NullArgument - ``repository_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method is must be implemented.*

        """
        # Implemented from awsosid template for -
        # osid.resource.BinLookupSession.get_bin_template
        if not self._can('lookup'):
            raise PermissionDenied()
        else:
            return self._provider_session.get_repository(repository_id)