class_docstr: A TestResult implementation which records its method calls.
code: def addSubTest(self, test, subtest, err):
      if err is None:
          self._events.append("addSubTestSuccess")
      else:
          self._events.append("addSubTestFailure")
      super().addSubTest(test, subtest, err)
  
imports: import unittest
label_desc: Use image node_id 1 for calling the LoggingResult obj's underlying member method code with example usage: obj.addSubTest(test, subtest, err) without return types