int entryCount(Set<Integer> buckets, boolean estimate) {
    assert buckets == null : "unexpected buckets " + buckets + " for region " + this;

    return getDataView().entryCount(this);
  }
Returns the number of entries in this region. Note that because of the concurrency properties
of the {@link RegionMap}, the number of entries is only an approximate. That is, other threads
may change the number of entries in this region while this method is being invoked.

@see RegionMap#size
geode-core/src/main/java/org/apache/geode/internal/cache/LocalRegion.java