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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def set_exc_info(self, exc_info):
 """Sets the exception information of a ``Future.`` Preserves tracebacks on Python 2. .. versionadded:: 4.0 """

        self._exc_info = exc_info
        self._log_traceback = True
        if not _GC_CYCLE_FINALIZERS:
            self._tb_logger = _TracebackLogger(exc_info)

        try:
            self._set_done()
        finally:
            # Activate the logger after all callbacks have had a
            # chance to call result() or exception().
            if self._log_traceback and self._tb_logger is not None:
                self._tb_logger.activate()
        self._exc_info = exc_info