@abc.abstractmethod<EOL><INDENT>def get_proficiencies_for_resources(self, resource_ids):<DEDENT>
return<EOL>
Gets a ``ProficiencyList`` relating to the given resources.

        :param resource_ids: the resource ``Ids``
        :type resource_ids: ``osid.id.IdList``
        :return: the returned ``Proficiency`` list
        :rtype: ``osid.learning.ProficiencyList``
        :raise: ``NullArgument`` -- ``resource_ids`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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