bucketizer.mean.exclude-nulls has the same behavior as
bucketizer.mean.exclude-nulls function returns the mean of all the values found for each bucket of a bucketized Geo Time Series™.
The associated location is the centroid of all the encountered locations. The associated elevation is the mean of the encountered elevations.
bucketizer.mean.exclude-nulls function can only be applied to values of type LONG or DOUBLE, when applied to STRING or BOOLEAN it does not return any value.
If a value is NULL in the bucket, the result is NULL