private synchronized void evaluate() {
		final var summary = new DoubleMomentStatistics();

		histogram = new Histogram.Builder(partition)
			.observer(summary)
			.build(sampling);

		statistics = summary.result();

		evaluated = true;
	}
Create a new sampling observation task.

@param sampling the sampling function
@param partition the partition used for the created histogram
jenetics.incubator/src/main/java/io/jenetics/incubator/stat/RunnableObservation.java