public void createRegionCache(TConsensusGroupId regionGroupId, int dataNodeId) {
    Optional.ofNullable(regionGroupCacheMap.get(regionGroupId))
        .ifPresent(cache -> cache.createRegionCache(dataNodeId, regionGroupId));
  }
Create a new RegionCache for the specified Region in the specified RegionGroup.

@param regionGroupId the index of the RegionGroup
@param dataNodeId the index of the DataNode where the Region resides
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/load/cache/LoadCache.java