@Override
    public void registerEngineName(final String name, final GremlinScriptEngineFactory factory) {
        if (null == name || null == factory) throw new NullPointerException();
        nameAssociations.put(name, factory);
    }
Registers a {@link GremlinScriptEngineFactory} to handle a language name.  Overrides any such association found
using the discovery mechanism.

@param name The name to be associated with the {@link GremlinScriptEngineFactory}
@param factory The class to associate with the given name.
@throws NullPointerException if any of the parameters is null.
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/jsr223/DefaultGremlinScriptEngineManager.java