code: def _random_string(length: int):
      """Generate a random string with given length. Used to generate multipart form data for /load request"""
      domain = string.ascii_lowercase + string.digits
      return "".join(random.choice(domain) for _ in range(length))
  
imports: import logging
  import os
  import random
  import string
  import time
  import pytest
  from falcon import testing
  from orion.core.io.database.pickleddb import PickledDB
  from orion.core.utils import generate_temporary_file
  from orion.serving.webapi import WebApi
  from orion.storage.backup import load_database
  from orion.storage.base import setup_storage
label_desc: Use image node_id 4 for calling a global function with example usage: _random_string(length) and returns: str