code: function(file) {
      this.fileName = "";
      this.length = 0;
      if (file) {
          this.localURL = file.localURL || file;
          this.length = file.size || 0;
      }
      // default is to write at the beginning of the file
      this.position = 0;
  
      this.readyState = 0; // EMPTY
  
      this.result = null;
  
      // Error
      this.error = null;
  
      // Event handlers
      this.onwritestart = null;   // When writing starts
      this.onprogress = null;     // While writing the file, and reporting partial file data
      this.onwrite = null;        // When the write has successfully completed.
      this.onwriteend = null;     // When the request has completed (either in success or failure).
      this.onabort = null;        // When the write has been aborted. For instance, by invoking the abort() method.
      this.onerror = null;        // When the write has failed (see errors).
  }
docs: This class writes to the mobile device file system.
  
  For Android:
  The root directory is the root of the file system.
  To write to the SD card, the file name is "sdcard/my_file.txt"
  
  @constructor
  @param file {File} File object containing file properties
  @param append if true write to the end of the file, otherwise overwrite the file