@abc.abstractmethod<EOL><INDENT>def get_resources_at_spatial_unit(self, spatial_unit):<DEDENT>
return<EOL>
Gets the current resource within the given spatial unit.

        :param spatial_unit: a spatial unit
        :type spatial_unit: ``osid.mapping.SpatialUnit``
        :return: the resources at the location
        :rtype: ``osid.mapping.ResourceLocationList``
        :raise: ``NullArgument`` -- ``spatial_unit`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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