The resource usage measurements are None when the Tracker is first initialized. So an exception is raised when a user attempts to call __str__ via str(tracker). There should be more explanation than None type does not have attribute .... If the measurements are None, the __str__ method should not crash but rather the content of the string should indicate that tracking has not yet begun.
The resource usage measurements are None when the
Trackeris first initialized. So an exception is raised when a user attempts to call__str__viastr(tracker). There should be more explanation thanNone type does not have attribute .... If the measurements are None, the__str__method should not crash but rather the content of the string should indicate that tracking has not yet begun.