BloggingSystem.Services.Validators.UserValidator.ValidateUsername C# (CSharp) Метод

        public static void ValidateUsername(string username)
        {
            if (username == null)
            {
                throw new ArgumentNullException("username", "Username cannot be null!");
            }

            if (username.Length < MinUsernameDisplayNameChars)
            {
                throw new ArgumentOutOfRangeException(
                    "username",
                    string.Format("Username cannot be less than {0} characters long!", MinUsernameDisplayNameChars));
            }

            if (username.Length > MaxUsernameDisplayNameChars)
            {
                throw new ArgumentOutOfRangeException(
                    "username",
                    string.Format("Username cannot be more than {0} characters long!", MaxUsernameDisplayNameChars));
            }

            if (username.Any(ch => !ValidUsernameChars.Contains(ch)))
            {
                throw new ArgumentOutOfRangeException("username", "Username contains invalid characters!");
            }
        }