text: /* Copyright (C) 2016 NooBaa */
  /** @typedef {typeof import('../sdk/nb')} nb */
  'use strict';
  
  const config = require('../../config');
  const postgres_client = require('./postgres_client');
  const mongo_client = require('./mongo_client');
  const dbg = require('./debug_module')(__filename);
  
  /**
   * @returns { nb.DBClient }
   */
  function instance() {
      switch (config.DB_TYPE) {
          case 'postgres':
              return postgres_client.instance();
          case 'mongodb':
              return mongo_client.instance();
          default: {
              const str = `NON SUPPORTED DB_TYPE ${config.DB_TYPE}`;
              dbg.error(str);
              throw new Error(str);
          }
      }
  }
  
  // EXPORTS
  exports.instance = instance;
  