@abc.abstractmethod<EOL><INDENT>def get_functions_by_search(self, function_query, function_search):<DEDENT>
return<EOL>
Gets the search results matching the given search query using the given search.

        :param function_query: the function query
        :type function_query: ``osid.authorization.FunctionQuery``
        :param function_search: the function search
        :type function_search: ``osid.authorization.FunctionSearch``
        :return: the returned search results
        :rtype: ``osid.authorization.FunctionSearchResults``
        :raise: ``NullArgument`` -- ``function_query`` or ``function_search`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure
        :raise: ``Unsupported`` -- ``function_search`` or ``function_query`` is not of this service

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