code: function EdmundsClient(config) {
    if (!(this instanceof EdmundsClient)) {
      return new EdmundsClient(config);
    }
  
    var defaultConfig = {};
    defaultConfig.responseFormat = 'json';
    defaultConfig.baseUrl = 'https://api.edmunds.com';
  
    this.config = extend(defaultConfig, config);
  
    if (!this.config.apiKey) {
      throw new Error('API key must be provided');
    }
  }
docs: The client constructor
  
  @param config - configuration object
  @constructor