Zipper() private method

private Zipper ( bool zip, string pathBackUpFiles ) : string
zip bool
pathBackUpFiles string
return string
        } // End Function

        public void AutoUppercaseLowercase(List<string> charsetSelecting, string pathBackupFiles, string extension, bool zip)
        {
            Interface.PleaseWait();
            Utility make = new Utility();

            make.Setting_UpFile(pathBackupFiles, extension);

            foreach (var item in charsetSelecting)
            {
                make.WorkFile.WriteLine(ConverterInUppercaseLowercase(item.ToString()));                
            }

            make.WorkFile.Close();
            extension = make.Zipper(zip, pathBackupFiles);
            make.GenerateOut(pathBackupFiles, extension);
           
        } // End Function 
        /// <summary>
        /// retun a list random of string
        /// </summary>
        /// <param name="charsetSelecting"></param>
        /// <param name="numberLine"></param>
        /// <param name="numberOfAllCombination"></param>
        /// <param name="saveFile"></param>
        /// <param name="zip"></param>       
        /// <param name="numberOfChar"></param>
        /// <param name="filePath"></param>
        /// <param name="extension"></param>
        public void GenerateRandomString(List<string> charsetSelecting, BigInteger numberLine, bool saveFile, BigInteger numberOfAllCombination,  bool zip,  int numberOfChar, string pathBackUpFiles, string extension)
        {
            Utility make = new Utility();
            BigInteger cpt = 0;

            if (saveFile)
            {
                BigInteger iMakeFile = 0;

                while  (numberOfAllCombination >= cpt)
                {
                    if (iMakeFile == 0)
                    {
                        make.Setting_UpFile(pathBackUpFiles,extension);
                    }

                    make.WorkFile.WriteLine(Aleatory(charsetSelecting, numberOfChar));
                    ++iMakeFile;
                    ++cpt;

                    if (iMakeFile >= numberLine || cpt >= numberOfAllCombination)
                    {
                        make.WorkFile.Flush();
                        make.WorkFile.Close();
                        extension=make.Zipper(zip, pathBackUpFiles);
                         make.GenerateOut(pathBackUpFiles,extension);
                        iMakeFile = 0;
                    }
                }
            }
            else
            {
                while (cpt <= numberOfAllCombination)
                {
                    if (cpt >= numberLine & numberLine != 0)
                        Environment.Exit(0);

                    Console.WriteLine(Aleatory(charsetSelecting, numberOfChar));
                    cpt++;
                }
            }
        }