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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 thread_exists(self, thread_id):
 """Check if a thread exists or has 404'd. Args: thread_id (int):
 Thread ID Returns: bool: Whether the given thread exists on this board. """

        return self._requests_session.head(
            self._url.thread_api_url(
                thread_id=thread_id
                )
        ).ok