code: def test_def(self):
      self.t(
          """
                      def f(x, y, z):
                          pass
                      def f(x = 34, y = 54, z):
                          pass
                 """
      )
  
file_path: catboost/contrib/tools/cython/Cython/Tests/TestCodeWriter.py
imports: from Cython.TestUtils import CythonTest
label_desc: Use image node_id 5 for calling the TestCodeWriter obj's underlying member method code with example usage: obj.test_def() without return types