def start(self, origin):
self.start_time = time.time()<EOL>self.pause_until = None<EOL>self.data.update(self._get_struct(origin, '<STR_LIT>'))<EOL>self.data_stack.append(self.data)<EOL>sys.settrace(self._trace)<EOL>return self._trace<EOL>
Start this Tracer.

Return a Python function suitable for use with sys.settrace().