code: def mock_platform(monkeypatch, request):
      monkeypatch.setattr(
          "graphviz.backend.viewing.PLATFORM", request.param
      )
      yield request.param
  
file_path: graphviz/tests/conftest.py
imports: import pytest
label_desc: Use image node_id 12 for calling a global function with example usage: mock_platform(monkeypatch, request) without return types