@Override
    public Map<String, Long> getCounts() {
        final Map<String, Long> ret = new HashMap<>();
        for (Map.Entry<String, AtomicLong> count : counts.entrySet()) {
            ret.put(count.getKey(), count.getValue().get());
        }
        return ret;
    }
A {@link Metrics} implementation that cannot be modified.

@author Bob Briody (http://bobbriody.com)
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/util/ImmutableMetrics.java