Is WindowedCount the right stat type to use in MetricsResourceMethodApplicationListener?

By default, an application is [configured](https://github.com/confluentinc/rest-utils/blob/67d9b070e700a5807ab584d51771ed7f92c2b255/core/src/main/java/io/confluent/rest/Application.java#L173) to keep two samples in a `SampledStat`, e.g., `WindowedCount`, each sample maintains a 30-second window. Typically, metrics are exposed by `JmxReporter`. When the value of an MBean is being retrieved, it calls the stat's `measure` method. In `WindowedCount`, `measure` simply combines all data points in all (two) samples to get the sum. Unless the MBean retrievals are well aligned with the start of a window with the intervals being (window size * # of samples), I don't see how it could report the right count.

For instance:
T: 0----5----[10]----15----[20]----25----[30]
W: |-----1-----|------2------|------3-------|

Let's assume the window size is 10, the metrics get collected every 10 seconds.
Collection 1 at 15: it returns the sum of (full window 1 and half of window 2), i.e., 0-15
Collection 2 at 25: it returns the sum of (full window 2 and half of window 3), i.e., 10-25
In this example, the values between 10-15 are repeatedly reported.

Can anyone please verify if this is the right understanding?