private ICachedMNode fillChildren(
      ICachedMNode par,
      int number,
      String prefix,
      BiFunction<ICachedMNode, String, ICachedMNode> nodeFactory) {
    String childName;
    ICachedMNode lastChild = null;
    for (int i = 0; i < number; i++) {
      childName = prefix + "_" + i;
      lastChild = nodeFactory.apply(par, childName);
      par.addChild(lastChild);
    }
    return lastChild;
  }
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