Elasticsearch 2.0 scripted_metric retrieve other script

Elastic Stack Elasticsearch
1

I have a plugin with some native scripts. Successfully install to ES 2.0:

module.registerScript("test-script", TestScript.Factory.class);

Is there any way to get this script inside another groovy script. Previously I used facets to get that script from script context. But ES 2.0 stop supporting facets.

Example: I want to get "test-script" inside "init_script" of aggregation

POST indext/_search
{
    "query": {"match_all": {}},
    "aggregations" : {
       "test" : {
           "scripted_metric" : {
           "init_script" : "* script = new TestScript() OR scriptService = _ctx.scriptService(); script = scriptService.compile('native','test-script', null); //worked with facet; script.run(params);",
           "map_script" : "test-script"
         }
      }
   }
}