private static Map<String, Set<String>> dealChildrenMap(final List<ResourceDO> metaList) {
        return metaList.stream()
                .filter(meta -> Objects.nonNull(meta) && StringUtils.isNotEmpty(meta.getId()))
                .collect(Collectors.toMap(ResourceDO::getParentId, ResourceUtil::convertIds, ListUtil::mergeSet));
    }
convert the list to a map, the key is the parent id, and the value is the set of child ids.

@param metaList the list to be converted
@return the map
shenyu-admin/src/main/java/org/apache/shenyu/admin/utils/ResourceUtil.java