code: def test_styleguide_input_file():
      """Verify we call StyleGuide.check_files with the filename."""
      app = mock.Mock()
      style_guide = api.StyleGuide(app)
      with mock.patch.object(style_guide, "check_files") as check_files:
          style_guide.input_file("file.py")
      check_files.assert_called_once_with(["file.py"])
  
file_path: flake8/tests/unit/test_legacy_api.py
imports: from __future__ import annotations
  from unittest import mock
  import pytest
  from flake8.api import legacy
  from flake8.formatting import base
label_desc: Use image node_id 8 for calling a global function with example usage: test_styleguide_input_file() without return types