@Override
  public void setPageIndex(int pid) {
    pageIndex = pid;
    this.pageBuffer.clear();
    this.pageBuffer.position(SchemaFileConfig.PAGE_HEADER_INDEX_OFFSET);
    ReadWriteIOUtils.write(pageIndex, pageBuffer);
    this.pageBuffer.clear();
  }
compatible constructor with no existing ref or lock
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/mtree/impl/pbtree/schemafile/SchemaPage.java