code: def test_wal_create_reopen_empty():
      WAL(filename, 64)
  
      wal = WAL(filename, 64)
      assert wal._page_size == 64
  
imports: import io
  import os
  import platform
  from unittest import mock
  import pytest
  from bplustree.node import LeafNode, FreelistNode
  from bplustree.memory import FileMemory, open_file_in_dir, WAL, ReachedEndOfFile, write_to_file
  from bplustree.const import TreeConf
  from .conftest import filename
  from bplustree.serializer import IntSerializer
label_desc: Use image node_id 11 for calling a global function with example usage: test_wal_create_reopen_empty() without return types