code: function update(options, allowUnknownKeys) {
      allowUnknownKeys = allowUnknownKeys || false;
      options = this.extractCredentials(options);
      AWS.util.each.call(this, options, function (key, value) {
        if (allowUnknownKeys || Object.prototype.hasOwnProperty.call(this.keys, key) ||
            AWS.Service.hasService(key)) {
          this.set(key, value);
        }
      });
    }
docs: @!group Loading and Setting Configuration Options
   
  @overload update(options, allowUnknownKeys = false)
  Updates the current configuration object with new options.
  
  @example Update maxRetries property of a configuration object
  config.update({maxRetries: 10});
  @param [Object] options a map of option keys and values.
  @param [Boolean] allowUnknownKeys whether unknown keys can be set on
  the configuration object. Defaults to `false`.
  @see constructor