public void ChangeName(string fileName)
        {
            Ensure.NotNullOrEmpty(fileName, "fileName");
            LocalFileCreator.EnsureValidName(fileName, null);

            string newPath = Path.Combine(Path.GetDirectoryName(AbsolutePath), fileName + Path.GetExtension(AbsolutePath));

            File.Move(AbsolutePath, newPath);
            SetFileRelatedProperties(newPath);
        }
        public void ChangeExtension(string fileExtension)
        {
            LocalFileCreator.EnsureValidName(null, fileExtension);

            string newFileName = Path.GetFileNameWithoutExtension(AbsolutePath);

            if (!String.IsNullOrEmpty(fileExtension))
            {
                newFileName += "." + fileExtension;
            }

            string newPath = Path.Combine(Path.GetDirectoryName(AbsolutePath));

            File.Move(AbsolutePath, newPath);
            SetFileRelatedProperties(newPath);
        }