docs: def _execute_example(self):
          "Handles the execution of the Example"
          test_benchmark = Benchmark()
          try:
              with Registry(), test_benchmark:
                  if accepts_arg(self.example.testfn):
                      self.example.testfn(self.context)
                  else:
                      self.context.inject_into_self(self.example.testfn)
                      self.example.testfn()
                  self.num_successes += 1
          except KeyboardInterrupt:
              # bubble interrupt for canceling spec execution
              raise
          except:
              raise
              self.num_failures += 1
          finally:
              self.example.user_time = test_benchmark.total_time