public RpnCalculator(ITokenInfoProvider tokenInfoProvider,
			IRpnInputValidator inputValidator)
		{
			_tokenInfoProvider = tokenInfoProvider;
			_inputValidator = inputValidator;
		}
		public RpnToParenthesisNotationConverterConverter(IRpnInputValidator inputValidator, 
			ITokenInfoProvider tokenInfoProvider)
		{
			_inputValidator = inputValidator;
			_tokenInfoProvider = tokenInfoProvider;
		}