code: def test_fci_download(tmp_path, monkeypatch):
      """Test download of FCI test data."""
      from satpy.demo import download_fci_test_data
  
      monkeypatch.chdir(tmp_path)
  
      def fake_download_url(url, nm):
          """Create a dummy tarfile.
  
          Create a dummy tarfile.
  
          Intended as a drop-in replacement for demo.utils.download_url.
          """
          _create_and_populate_dummy_tarfile(nm)
  
      with mock.patch(
          "satpy.demo.fci.utils.download_url", new=fake_download_url
      ):
          files = download_fci_test_data(tmp_path)
      assert len(files) == 3
      assert files == ["fci-rc0", "fci-rc1", "fci-rc2"]
      for f in files:
          assert os.path.exists(f)
  
imports: from __future__ import annotations
  import contextlib
  import io
  import os
  import sys
  import tarfile
  import unittest
  from collections import defaultdict
  from unittest import mock
  import pytest
label_desc: Use image node_id 2 for calling a global function with example usage: test_fci_download(tmp_path, monkeypatch) without return types