public function task( $args ) {

		$this->log( sprintf( 'Course data calculation task called for course %1$d with args: %2$s', $args['post_id'], wp_json_encode( $args ) ) );

		$course = llms_get_post( $args['post_id'] );

		// Only process existing courses.
		if ( ! $course instanceof LLMS_Course ) {
			$this->log( sprintf( 'Course data calculation task skipped for course %1$d.', $args['post_id'] ) );
			return false;
		}

		// Lock the course against duplicate processing.
		$course->set( 'temp_calc_data_lock', 'yes' );

		// Get saved data or empty array when on first page.
		$data = ( 1 !== $args['page'] ) ? $course->get( 'temp_calc_data' ) : array();

		// Merge with the defaults.
		$data = $this->get_task_data( $data );

		// Perform the query.
		$query = new LLMS_Student_Query( $args );

		foreach ( $query->get_students() as $student ) {

			// Progress, all students counted here.
			$data['students']++;
			$data['progress'] = $data['progress'] + $student->get_progress( $args['post_id'] );

			// Grades only counted when a student has taken a quiz.
			// If a student hasn't taken it, we don't count it as a 0 on the quiz.
			$grade = $student->get_grade( $args['post_id'] );

			// Only check actual quiz grades.
			if ( is_numeric( $grade ) ) {
				$data['quizzes']++;
				$data['grade'] = $data['grade'] + $grade;
			}
		}

		return $this->task_complete( $course, $data, $query->is_last_page() );

	}