async searchUsersByCredentials(request) {
    const strategy = request.getString("strategy");
    const lang = request.getLangParam();
    const { from, size, searchBody } = request.getSearchParams();

    this.assertIsStrategyRegistered(strategy);

    const searchMethod = this.getStrategyMethod(strategy, "search");

    if (!searchMethod) {
      throw kerror.get(
        "plugin",
        "strategy",
        "missing_optional_method",
        "search",
        strategy,
      );
    }

    if (lang === "koncorde") {
      searchBody.query = await this.translateKoncorde(searchBody.query || {});
    }

    this.assertNotExceedMaxFetch(size - from);

    return searchMethod(searchBody, { from, size });
  }
Given a credentials related search query, returns matched users' kuid.

@param {Request} request
@returns {Promise<Object>}