If we now rerun the code to traverse all cars and their sensor readings, we are again confronted with the same problem that we had before, we end up with some leaves of our object graph being null.

如果我们重新运行代码遍历所有的汽车以及它们的感应器读数，我们将遭遇和前面一样的问题，我们获得的对象图表某些叶子节点为空。

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If we now rerun the code to traverse all cars and their sensor readings, we are again confronted with the same problem that we had before, we end up with some leaves of our object graph being null.

如果我们重新运行代码遍历所有的汽车以及它们的感应器读数，我们将遭遇和前面一样的问题，我们获得的对象图表某些叶子节点为空。

youdao