code: function writeText(file, text, allowBlindWrite) {
          var result = new $.Deferred(),
              options = {};
  
          if (allowBlindWrite) {
              options.blind = true;
          }
  
          file.write(text, options, function (err) {
              if (!err) {
                  result.resolve();
              } else {
                  result.reject(err);
              }
          });
  
          return result.promise();
      }
docs: Asynchronously writes a file as UTF-8 encoded text.
  @param {!File} file File to write
  @param {!string} text
  @param {boolean=} allowBlindWrite Indicates whether or not CONTENTS_MODIFIED
  errors---which can be triggered if the actual file contents differ from
  the FileSystem's last-known contents---should be ignored.
  @return {$.Promise} a jQuery promise that will be resolved when
  file writing completes, or rejected with a FileSystemError string constant.