code: function writeFile(filePath, contents) {
    return new Promise((resolve, reject) => {
      fs.writeFile(filePath, contents, 'utf-8', (err, file) => {
        err ? reject(err) : resolve();
      })
    });
  }
docs: Writes a file to disk.
  
  @param {string} filePath The file path to write to.
  @param {string} contents A UTF-8 encoded string of the file contents.
  @return {Promise<void>} Resolves when the file has been written successfully.