code: def test_filter_files_by_extension():
      sources_cpp = ["a.cpp", "b.cpp"]
      sources_pyx = ["c.pyx"]
      sources = sources_cpp + sources_pyx
      assert filter_files_by_extension(sources, ".cpp") == (
          sources_cpp,
          sources_pyx,
      )
      assert filter_files_by_extension(sources, ".pyx") == (
          sources_pyx,
          sources_cpp,
      )
      assert filter_files_by_extension(sources, ".cu") == ([], sources)
      assert filter_files_by_extension(sources_cpp, ".cpp") == (
          sources_cpp,
          [],
      )
      assert filter_files_by_extension(sources_cpp, ".pyx") == (
          [],
          sources_cpp,
      )
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_filter_files_by_extension() without return types