How to use the ace-builds/src-noconflict/ext-language_tools.addCompleter function in ace-builds

logger.log("sendChange", delta);
    lsClient.nextChange("/main.ts", delta);
  });

  lsClient.getErrors$("/main.ts").subscribe(errors => {
    if (errors.length) {
      logger.log("rcvError", errors);
    } else {
      logger.log("clearError");
    }
    editorSession.setAnnotations(errors);
  });

  if (lsClient.useComplete) {
    const completer = createCompleter(lsClient.languageServiceSession);
    langTools.addCompleter(completer);
  }

  return editor;
}