public default Optional<Customizer[]> getCustomizers(){
        return getCustomizers(null);
    }
Gets the list of all {@link Customizer} implementations to assign to a new {@link GremlinScriptEngine}. This is
the same as doing {@code getCustomizers(null)}.
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/jsr223/GremlinPlugin.java