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The default behavior of the Detector class is to crash when a requested Detector is not present (so users will be alerted if they make a typo, for example).  But this is often not desired behavior during production running when Detectors are being added/removed from the data stream on a run-to-run basis. To change that behavior use a constructor like Detector('MyDetectorName',accept_missing=True).  With this flag, all methods of the Detector will return None, just as it would if it will was missing in every event.

Accessing Data While Running

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