code: def merge(x0: str, x1: str, x2: str) -> str:
      return sha1((x0 + x1 + x2).encode()).hexdigest()
  
file_path: ray/python/ray/workflow/tests/test_storage_failure.py
imports: from hashlib import sha1
  import tempfile
  import pytest
  import ray
  from ray import workflow
  from ray.workflow.storage.debug import DebugStorage
  from ray.workflow.workflow_storage import STEP_OUTPUTS_METADATA
  from ray.workflow.common import asyncio_run
  from ray.workflow.storage.filesystem import FilesystemStorageImpl
  from ray.workflow.tests.utils import _alter_storage
label_desc: Use image node_id 4 for calling a global function with example usage: merge(x0, x1, x2) and returns: sha1