code: function (options, callback) {
        if (!('headers' in options)) {
          options.headers = {};
        }
  
        options.json = true;
        options.headers['User-Agent'] = Poloniex.USER_AGENT;
        options.strictSSL = Poloniex.STRICT_SSL;
        options.timeout = Poloniex.TIMEOUT;
  
        return new Promise(function (resolve, reject) {
          request(options, function (err, response, body) {
            // Empty response
            if (!err && (typeof body === 'undefined' || body === null)) {
              err = new Error('Empty response from remote server');
            }
  
            if (err) {
              reject(err);
            }
  
            else {
              resolve(body);
            }
  
            if (typeof callback === 'function') {
              callback(err, body);
            }
          });
        });
      }
docs: Make an API request