code: function WPOAuth(options){
    if (!(this instanceof WPOAuth)) return new WPOAuth(options);
  
    // Options
    this.opts = globals = options || {};
    for (var attr in def){
      this.opts[attr] = this.opts[attr] || def[attr];
    }
  
    this._code = this.opts.code;
  
    // Error exceptions
    if (!this.opts.client_id) {
      throw new Error('`client_id` is required');
    }
  
    if (!this.opts.client_secret) {
      throw new Error('`client_secret` is required');
    }
  }
docs: Class constructor
  
  @param {Object} options
  @api public