public void WritingToFileUpdatesTally()
        {
            using (var writer
                = new TallyKeepingFileStreamWriter(File.Open(fileName, FileMode.Append, FileAccess.Write, FileShare.Read)))
            {
                writer.Write("12345");
                writer.Flush();

                Assert.AreEqual(5L, writer.Tally);
            }
        }
        public void WritingToFileWithEncodingUpdatesTally()
        {
            using (var writer
                = new TallyKeepingFileStreamWriter(File.Open(fileName, FileMode.Append, FileAccess.Write, FileShare.Read),
                                                                                Encoding.UTF32))
            {
                writer.Write("12345");
                writer.Flush();

                Assert.AreEqual(20L, writer.Tally); // BOM is not part of tally - minimal fidelity loss on new files.
            }
        }