code: def test_list_of_float64(self):
      self.run_test(
          "def list_of_float64(l): return [2. * _ for _ in l]",
          [1.0, 2.0],
          list_of_float64=[List[np.float64]],
      )
  
imports: import numpy
  import unittest
  from pythran.typing import *
  from pythran.tests import TestEnv
label_desc: Use image node_id 7 for calling the TestConversion obj's underlying member method code with example usage: obj.test_list_of_float64() without return types