@Override
    public GremlinScriptEngine getEngineByExtension(final String extension) {
        if (!extensionToName.containsKey(extension))  {
            final GremlinScriptEngine engine = super.getEngineByExtension(extension);
            registerLookUpInfo(engine, engine.getFactory().getEngineName());
            return engine;
        }

        return cache.get(extensionToName.get(extension));
    }
Gets a {@link GremlinScriptEngine} from cache or creates a new one from the {@link GremlinScriptEngineFactory}.
<p/>
{@inheritDoc}
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/jsr223/CachedGremlinScriptEngineManager.java