code: def test_remove() -> None:
      with init_mock_client():
          bucket_name = "mock-bucket"
          backend = GCSArtifactStore(bucket_name)
          client = google.cloud.storage.Client()
  
          artifact_id = "dummy-uuid"
          backend.write(artifact_id, io.BytesIO(b"Hello"))
          assert len(list(client.bucket(bucket_name).list_blobs())) == 1
  
          backend.remove(artifact_id)
          assert len(list(client.bucket(bucket_name).list_blobs())) == 0
  
imports: from __future__ import annotations
  import contextlib
  import io
  import os
  from typing import Dict
  from typing import Optional
  from typing import TYPE_CHECKING
  from unittest.mock import patch
  import google.cloud.storage
  import pytest
  from optuna.artifacts import GCSArtifactStore
  from optuna.artifacts.exceptions import ArtifactNotFound
label_desc: Use image node_id 3 for calling a global function with example usage: test_remove() without return types