code: function createServerEtag(inode, mTime) {
  
    // Create a string from the file inode and mtime.
    const str = inode.toString() + mTime.getTime().toString();
  
    return crypto.createHash('md5').update(str).digest('hex');
  }
docs: @function createServerEtag
  @private
  
  @param: inode {Number} The file inode number
  @param: mTime {Date} JavaScript date object (returned from mtime in fs.stat call).
  
  @returns: an etag for use in HTTP headers.