public long getOpenIteratorCount() {
        return openIteratorCount.get();
    }
Utility class which can be used by providers to keep a count of the number of
open iterators to the underlying storage. Please note that, by default, this does
not maintain the count unless explicitly plugged-in by the provider implementation.
<p>
As an example on how to plugin-in the counter in the provider implementation
check TinkerGraphIterator.

@see Traversal#close()
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/util/iterator/StoreIteratorCounter.java