docs: function multiple(pool, fn, queries, callback) {
    let queryObjects = queries.map(query => {
      if (typeof query === 'string') {
        return { text: query, values: [] };
      }
  
      return Object.assign({ values: [] }, query);
    });
  
    if (callback && typeof callback === 'function') {
      return fn(pool, queryObjects, callback);
    }
  
    return new Promise((resolve, reject) => {
      fn(pool, queryObjects, (error, result) => {
        if (error) {
          return reject(error);
        }
  
        resolve(result);
      });
    });
  }