private static function get_assignments_assignment_structure() {
        return new external_single_structure(
            array(
                'id' => new external_value(PARAM_INT, 'assignment id'),
                'cmid' => new external_value(PARAM_INT, 'course module id'),
                'course' => new external_value(PARAM_INT, 'course id'),
                'name' => new external_value(PARAM_TEXT, 'assignment name'),
                'nosubmissions' => new external_value(PARAM_INT, 'no submissions'),
                'submissiondrafts' => new external_value(PARAM_INT, 'submissions drafts'),
                'sendnotifications' => new external_value(PARAM_INT, 'send notifications'),
                'sendlatenotifications' => new external_value(PARAM_INT, 'send notifications'),
                'sendstudentnotifications' => new external_value(PARAM_INT, 'send student notifications (default)'),
                'duedate' => new external_value(PARAM_INT, 'assignment due date'),
                'allowsubmissionsfromdate' => new external_value(PARAM_INT, 'allow submissions from date'),
                'grade' => new external_value(PARAM_INT, 'grade type'),
                'timemodified' => new external_value(PARAM_INT, 'last time assignment was modified'),
                'completionsubmit' => new external_value(PARAM_INT, 'if enabled, set activity as complete following submission'),
                'cutoffdate' => new external_value(PARAM_INT, 'date after which submission is not accepted without an extension'),
                'gradingduedate' => new external_value(PARAM_INT, 'the expected date for marking the submissions'),
                'teamsubmission' => new external_value(PARAM_INT, 'if enabled, students submit as a team'),
                'requireallteammemberssubmit' => new external_value(PARAM_INT, 'if enabled, all team members must submit'),
                'teamsubmissiongroupingid' => new external_value(PARAM_INT, 'the grouping id for the team submission groups'),
                'blindmarking' => new external_value(PARAM_INT, 'if enabled, hide identities until reveal identities actioned'),
                'hidegrader' => new external_value(PARAM_INT, 'If enabled, hide grader to student'),
                'revealidentities' => new external_value(PARAM_INT, 'show identities for a blind marking assignment'),
                'attemptreopenmethod' => new external_value(PARAM_TEXT, 'method used to control opening new attempts'),
                'maxattempts' => new external_value(PARAM_INT, 'maximum number of attempts allowed'),
                'markingworkflow' => new external_value(PARAM_INT, 'enable marking workflow'),
                'markingallocation' => new external_value(PARAM_INT, 'enable marking allocation'),
                'requiresubmissionstatement' => new external_value(PARAM_INT, 'student must accept submission statement'),
                'preventsubmissionnotingroup' => new external_value(PARAM_INT, 'Prevent submission not in group', VALUE_OPTIONAL),
                'submissionstatement' => new external_value(PARAM_RAW, 'Submission statement formatted.', VALUE_OPTIONAL),
                'submissionstatementformat' => new external_format_value('submissionstatement', VALUE_OPTIONAL),
                'configs' => new external_multiple_structure(self::get_assignments_config_structure(), 'configuration settings'),
                'intro' => new external_value(PARAM_RAW,
                    'assignment intro, not allways returned because it deppends on the activity configuration', VALUE_OPTIONAL),
                'introformat' => new external_format_value('intro', VALUE_OPTIONAL),
                'introfiles' => new external_files('Files in the introduction text', VALUE_OPTIONAL),
                'introattachments' => new external_files('intro attachments files', VALUE_OPTIONAL),
            ), 'assignment information object');
    }