System.Security.Tests.SecureStringTests.AppendChar C# (CSharp) Method

        public static void AppendChar()
        {
            using (SecureString testString = CreateSecureString(string.Empty))
            {
                var expected = new StringBuilder();
                foreach (var ch in new[] { 'a', 'b', 'c', 'd' })
                {
                    testString.AppendChar(ch);
                    expected.Append(ch);
                    AssertEquals(expected.ToString(), testString);
                }
                AssertEquals(expected.ToString(), testString); // check last case one more time for idempotency
            }
        }