Handles the execution of the Example

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