public void Save()
        {
            if (String.IsNullOrEmpty(_repository.SourceFile))
            {
                SaveAs();
                return;
            }

            try
            {
                _repository.SaveToFile(Document, _repository.SourceFile, _repository.SourceType);
                Title = ProjectName + $" - {_repository.SourceFile}";
                UnmodifyDocument();
            }
            catch (Exception e)
            {
                ShowError(e);
            }
        }