public void AppendJoin()
        {
            var list = new List<string> {"Fizz", "Buzz"};

            // Type
            var @this = new StringBuilder();


            // Exemples
            @this.AppendJoin(",", list.ToArray()); // return "Fizz,Buzz";

            // Unit Test
            Assert.AreEqual("Fizz,Buzz", @this.ToString());
        }
 public static StringBuilder AppendJoin(
     this StringBuilder stringBuilder, IEnumerable <string> values, string separator = ", ")
 => stringBuilder.AppendJoin(values, (sb, value) => sb.Append(value), separator);
 public static StringBuilder AppendJoin(
     this StringBuilder stringBuilder, string separator, params string[] values)
 => stringBuilder.AppendJoin(values, (sb, value) => sb.Append(value), separator);