code: def test_attachments(trials):
      blob = b"abcde"
      assert "aname" not in trials.attachments
      trials.attachments["aname"] = blob
      assert "aname" in trials.attachments
      assert trials.attachments["aname"] == blob
      assert trials.attachments["aname"] == blob
  
      blob2 = b"zzz"
      trials.attachments["aname"] = blob2
      assert "aname" in trials.attachments
      assert trials.attachments["aname"] == blob2
      assert trials.attachments["aname"] == blob2
  
      del trials.attachments["aname"]
      assert "aname" not in trials.attachments
  
imports: import pickle
  import os
  import signal
  import subprocess
  import sys
  import traceback
  import threading
  import time
  import unittest
  import numpy
  import nose
  import nose.plugins.skip
  from hyperopt.base import JOB_STATE_DONE, STATUS_OK
  from hyperopt.mongoexp import parse_url
  from hyperopt.mongoexp import MongoTrials
  from hyperopt.mongoexp import MongoWorker
  from hyperopt.mongoexp import ReserveTimeout
  from hyperopt.mongoexp import as_mongo_str
  from hyperopt.mongoexp import main_worker_helper
  from hyperopt.mongoexp import MongoJobs
  from hyperopt.fmin import fmin
  from hyperopt import hp, rand
  import hyperopt.tests.test_base
  from hyperopt.tests.unit.test_domains import gauss_wave2
label_desc: Use image node_id 8 for calling a global function with example usage: test_attachments(trials) without return types