code: def test_isnan_(self):
      self.run_test(
          "def isnan_(a):\n from math import isnan\n return isnan(a)",
          1,
          isnan_=[int],
      )
  
imports: from pythran.tests import TestEnv
label_desc: Use image node_id 5 for calling the TestMath obj's underlying member method code with example usage: obj.test_isnan_() without return types