code: def test_str_hexdigits(self):
      self.run_test(
          "def str_hexdigits(): import string; return string.hexdigits",
          str_hexdigits=[],
      )
  
imports: from pythran.tests import TestEnv
  from pythran.typing import List
  import unittest
label_desc: Use image node_id 16 for calling the TestStr obj's underlying member method code with example usage: obj.test_str_hexdigits() without return types