/// <summary>
        /// Make a choice.
        /// </summary>
        /// <param name="opponentLastChoice">The last choice of the opponent.</param>
        /// <returns>
        /// The choice.
        /// </returns>
        public override CooperationChoice Choose(CooperationChoice opponentLastChoice)
        {
            if (opponentLastChoice == CooperationChoice.None)
            {
                return CooperationChoice.Cooperate;
            }

            return opponentLastChoice;
        }
 /// <summary>
 /// Make a choice.
 /// </summary>
 /// <param name="opponentLastChoice">The last choice of the opponent.</param>
 /// <returns>
 /// The choice.
 /// </returns>
 public override CooperationChoice Choose(CooperationChoice opponentLastChoice)
 {
     return CooperationChoice.Cooperate;
 }