static void moveToUpdateBuffer(ICachedMNode par, String childName) {
    ICachedMNodeContainer.getCachedMNodeContainer(par).appendMNode(par.getChild(childName));
    ICachedMNodeContainer.getCachedMNodeContainer(par).transferAllBufferReceivingToFlushing();
    ICachedMNodeContainer.getCachedMNodeContainer(par)
        .moveMNodeFromNewChildBufferToCache(childName);
    ICachedMNodeContainer.getCachedMNodeContainer(par).updateMNode(childName);
  }
related methods shall be merged further: {@linkplain SchemaFile#reEstimateSegSize}
,{@linkplain PageManager#reEstimateSegSize}
iotdb-core/datanode/src/test/java/org/apache/iotdb/db/metadata/mtree/schemafile/SchemaFileTest.java