code: def test_file_counts_by_category_adds_counts():
      s = stats.Stats()
      s.init_file("foo", 10),
      s.init_file("bar", 10),
      s.init_file("wandb/bar", 10),
      assert s.file_counts_by_category() == stats.FileCountsByCategory(
          artifact=0, wandb=1, media=0, other=2
      )
  
file_path: wandb/tests/pytest_tests/unit_tests/test_file_stats.py
imports: import pytest
  from wandb.filesync import stats
label_desc: Use image node_id 2 for calling a global function with example usage: test_file_counts_by_category_adds_counts() without return types