code: function saveConnections(config, callback) {
    // only save "connections" part, nothing else from config object
    let saveCfg = {
      connections: config.util.toObject(config.connections).map(function(c) {
        delete c.connectionId;
        return c;
      })
    };
    fs.writeFile(getConfigPath('connections'), JSON.stringify(saveCfg, null, 2), function (err) {
      if (typeof callback === 'function') callback(err ? err : null);
    });
  }
docs: functions related to new config files from node-config ========== Helper to save all current connections defined inside config object into
  configuration file for connections
  
  @see getConfigPath
  @param {object} config - config object to save configurations from
  @param {function} callback - callback after save, error object as first param on failure