Add errata ids to a dataset handle record.

        To call this method, you do not need to provide the
        PID of the dataset. Instead, the PID string is derived
        from the dataset id and the version number.

        :param errata_ids: Mandatory. A list of errata ids (strings)
            to be added to the handle record.

        :param drs_id: Mandatory. The dataset id of the dataset
            to whose handle record the errata ids are to be
            added. (This is needed because the handle is found
            by making a hash over dataset id and version number).

        :param version_number: Mandatory. The version number of the
            dataset to whose handle record the errata ids are to be
            added. (This is needed because the handle is found by
            making a hash over dataset id and version number).

def add_errata_ids(self, **args):
        '''
        Add errata ids to a dataset handle record.

        To call this method, you do not need to provide the
        PID of the dataset. Instead, the PID string is derived
        from the dataset id and the version number.

        :param errata_ids: Mandatory. A list of errata ids (strings)
            to be added to the handle record.

        :param drs_id: Mandatory. The dataset id of the dataset
            to whose handle record the errata ids are to be
            added. (This is needed because the handle is found
            by making a hash over dataset id and version number).

        :param version_number: Mandatory. The version number of the
            dataset to whose handle record the errata ids are to be
            added. (This is needed because the handle is found by
            making a hash over dataset id and version number).
        '''

        # Check args:
        mandatory_args = ['drs_id', 'version_number', 'errata_ids']
        esgfpid.utils.check_presence_of_mandatory_args(args, mandatory_args)
        esgfpid.utils.check_noneness_of_mandatory_args(args, mandatory_args)

        # Perform metadata update
        assistant = esgfpid.assistant.errata.ErrataAssistant(
            coupler=self.__coupler,
            prefix=self.prefix
        )
        assistant.add_errata_ids(
            drs_id=args['drs_id'],
            version_number=args['version_number'],
            errata_ids=args['errata_ids']
        )