private void AddFile(object obj)
        {
            bool isAlreadyListed =
                _blackListedFiles.Any(f => f.FileExtension == _newExtension && f.FileName == _newFilename);

            if (!isAlreadyListed)
            {
                if (!string.IsNullOrEmpty(_newExtension))
                {
                    var blackFile = new BlackListedFile
                    {
                        FileName      = _newFilename,
                        FileExtension = "." + _newExtension,
                    };

                    _databaseService.AddBlacklistedFile(blackFile);

                    BlackListedFiles = _databaseService.GetBlackListedFiles();

                    NewFilename  = "*";
                    NewExtension = string.Empty;

                    MessageBox.Show(Resources.ConfigurationViewModel_AddFile_File_added_to_Blacklist_,
                                    Resources.ConfigurationViewModel_AddFile_Info, MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                else
                {
                    MessageBox.Show(
                        Resources.ConfigurationViewModel_AddFile_File_not_added_to_Blacklist__Extension_cannot_be_empty_,
                        Resources.ConfigurationViewModel_AddFile_Warning, MessageBoxButtons.OK, MessageBoxIcon.Warning);
                }
            }
        }