code: def test_non_mockfs():
      assert "mock" not in _fsspec_registry
      assert "bz2" in _fsspec_registry
  
file_path: datasets/tests/test_filesystem.py
imports: import importlib
  import os
  import fsspec
  import pytest
  from fsspec import register_implementation
  from fsspec.registry import _registry
  from datasets.filesystems import COMPRESSION_FILESYSTEMS, extract_path_from_uri, is_remote_filesystem
  from .utils import require_lz4, require_zstandard
label_desc: Use image node_id 2 for calling a global function with example usage: test_non_mockfs() without return types