_incFile(callback) {
    debug('_incFile', this.filename);
    const ext = path.extname(this._basename);
    const basename = path.basename(this._basename, ext);
    const tasks = [];

    if (this.zippedArchive) {
      tasks.push(
        function (cb) {
          const num = this._created > 0 && !this.tailable ? this._created : '';
          this._compressFile(
            path.join(this.dirname, `${basename}${num}${ext}`),
            path.join(this.dirname, `${basename}${num}${ext}.gz`),
            cb
          );
        }.bind(this)
      );
    }

    tasks.push(
      function (cb) {
        if (!this.tailable) {
          this._created += 1;
          this._checkMaxFilesIncrementing(ext, basename, cb);
        } else {
          this._checkMaxFilesTailable(ext, basename, cb);
        }
      }.bind(this)
    );

    asyncSeries(tasks, callback);
  }
TODO: add method description.
@param {function} callback - TODO: add param description.
@returns {undefined}