code: def test_varnames_default():
      def f(x, y=3):
          pass
  
      assert varnames(f) == (("x",), ("y",))
  
file_path: catboost/contrib/python/pluggy/py2/tests/test_helpers.py
imports: from pluggy.hooks import varnames
  from pluggy.manager import _formatdef
  import sys
  import pytest
label_desc: Use image node_id 2 for calling a global function with example usage: test_varnames_default() without return types