code: def test_data_write_empty(with_datastore):
      """Write empty record with zero length, then write next record."""
      ds = with_datastore
      ds._write_data(b"\x01" * (32768 - 7 - 7 - 7))
      ds._write_data(b"\x02" * (1))
      ds.close()
      s = os.stat(FNAME)
      assert s.st_size == 32768 + 7 + 1
  
file_path: wandb/tests/pytest_tests/unit_tests/test_datastore.py
imports: import json
  import os
  import pytest
  import wandb
  from wandb.proto import wandb_internal_pb2
label_desc: Use image node_id 7 for calling a global function with example usage: test_data_write_empty(with_datastore) without return types