code: def test_dict_keys(self):
      return self.run_test(
          "def dict_keys(a): return sorted([ x*2 for x in a.keys()])",
          {1: "a", 2: "b"},
          dict_keys=[Dict[int, str]],
      )
  
imports: from pythran.tests import TestEnv
  from pythran.typing import Dict, List
label_desc: Use image node_id 22 for calling the TestDict obj's underlying member method code with example usage: obj.test_dict_keys() and returns: self