code: def start(self, origin):
          
          self.start_time = time.time()
          self.pause_until = None
          self.data.update(self._get_struct(origin, 'origin'))
          self.data_stack.append(self.data)
          sys.settrace(self._trace)
          return self._trace
docs: Start this Tracer.
  
          Return a Python function suitable for use with sys.settrace().