// Constructor

        public LineDisconnectedState(Speaker speaker)
        {
            _speaker = speaker;
        }
 public DiallingState(Speaker speaker)
 {
     _speaker = speaker;
 }
        // Constructor

        public LineBusyState(Speaker speaker)
        {
            _speaker = speaker;
        }
        // Constructor

        public ConversationState(Speaker speaker, Microphone microphone)
        {
            _speaker = speaker;
            _microphone = microphone;
        }
        // Constructor

        public WaitForAnswerState(Speaker speaker)
        {
            _speaker = speaker;
        }