RunningStatistics and ThresholdedRunningStatistics does not pass all unit tests
The RunningStatistics and ThresholdedRunningStatistics index functions does not pass all the unit tests. Some test fails because the mask is not preserved in the process e.g., when using np.concatenate and np.where. Other tests fails if another statistics than "max" is used and some fails because of the padding with zeros in the start and end which can give lower aggregated values.