def METHOD_NAME(cls, exclude_user=None):
    """
    Get all reports.
    If ``exclude_user`` is provided, exclude all reports for
    the comments that the given user has already reviewed/reported.
    """
    reports = cls.query.filter(cls.resolved_at.is_(None))
    if exclude_user is not None:
        # get all comment ids that the given user has already reviewed/reported
        existing_reported_comments = (
            db.session.query(cls.comment_id)
            .filter_by(reported_by_id=exclude_user.id)
            .distinct()
        )
        # exclude reports for those comments
        reports = reports.filter(~cls.comment_id.in_(existing_reported_comments))
    return reports